Fer FALCON II Installation, Servicing & User Instructions
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Appr. nr. B99.06 A - CE 0461 AU 0447
3543544/0 - 01/01
INSTALLATION,
SERVICING AND
USER INSTRUCTIONS
G.C. NO: 47-267-24
COPPER WALL-MOUNTED COMBINATION,
GAS FIRED BOILER FOR CENTRAL HEATING
AND DOMESTIC HOT WATER PRODUCTION,
FAN ASSISTED, ROOM SEALED COMPARTMENT,
ELECTRONIC FLAME IGNITION AND CONTROL
FALCON II
CE mark documents that the FER gas appliances comply with the requirement contained in European
directives applicable to them.
In particular, the appliances comply with the following CEE directives and the technical specifications
provided from them:
•
Gas appliances directive 90/396
•
Efficiencies directive 92/42
•
Low tension directive 73/23 (modified from the 93/68)
•
Electromagnetic compatibility directive 89/396 (modified from the 93/68)
Year 2000 Compliance Declaration
We will guarantee that this products is altogether suitable for the data change in the Year 2000 (boiler has no
dependence from date change) and that no disruptions will occur which is caused by this product.
IMPORTANT
Your "benchmark" Installation, Commissioning and Service Record Log Book will be enclosed in
your customer information pack.
"This record must be completed and left with the end user"
"All CORGI Registered Installers carry a CORGI ID card and have a registration number. Both should
be recorded in your central heating log book. You can check the installer's CORGI registration by
calling CORGI on 01256 372300".
FER is a member of the Benchmark initiative and fully supports the aims of the programme. Benchmark
has been introduced to improve the standards of installation and commissioning of central heating
systems in the UK and to encourage the regular servicing of all central heating systems to ensure
safety and efficiency.
Please see installation and servicing guidelines.
INDEX
1. DESCRIPTION......................................................................................................................................... 3
2. TECHNICAL AND DIMENSIONAL CHARACTERISTICS .......................................................................... 4
3. INSTALLATION DETAILS ........................................................................................................................ 9
4. COMMISSIONING AND TESTING........................................................................................................ 21
5. ADJUSTMENT AND GAS CONVERSION.............................................................................................. 22
6. MAINTENANCE AND CLEANING ....................................................................................................... 24
7. REPLACEMENT OF PARTS .................................................................................................................... 26
8. FAULT FINDING................................................................................................................................... 31
9. ELECTRICAL AND FUNCTIONAL SCHEME .......................................................................................... 38
10. USER INSTRUCTIONS ........................................................................................................................ 40
The Falcon II is defined as a “room sealed” combination boiler, all air required for combustion is taken from outside the
room in which it is installed. It is a new high performance gas fired heat generator for central heating and domestic hot
water production. A special feature of this boiler is its built-in electronic flame ignition and control unit making burner
operation completely automatic and safe. The main components are as follows:
• Copper heat exchanger consisting of three finned tubes specifically shaped for high efficiency.
• There are three copper coils inserted in the three heating circuit tubes. These represent the domestic hot water heat
exchanger. Their shape and high exchange surface area enable the full output of the boiler to be absorbed.
• Ceramic fibre insulated combustion chamber
• 16 stainless steel bladed burners specifically designed for this boiler.
• Fan for discharge of combustion products and intake of combustion air.
• Differential air pressure switch. For safety reasons, this ensures the burner ignites only when the fan is
functioning correctly.
• Hermetically sealed compartment made from corrosion-resistant steel enclosing the above components.
• Combination gas safety valve with modulator, complete with pressure stabiliser.
• Flowmeter giving the domestic hot water circuit precedence over the central heating circuit.
• Pressure relief valve for the central heating circuit set to open at 3 bar.
• Built-in Expansion vessel.
• Variable speed pump.
• Central heating flow temperature adjustment thermostat.
• Domestic hot water flow temperature adjustment thermostat.
• Central heating limit thermostat.
• Overheat safety thermostat.
• Electronic control unit for automatic flame ignition and control.
• Central heating low water pressure cut off switch.
• Domestic hot water flow temperature sensor.
• Central heating flow temperature sensor.
1.02 Instructions and regulations
Assembly, installation, first start up and maintenance must be carried out by competent persons only, in accordance
with all current technical regulations and directives.
C.O.S.H.H.
Materials used in the manufacture of this appliance are non hazardous and no special precautions are required
when servicing.
Related Documents
This appliance must be installed strictly in accordance with these instructions.
The Gas Safety Regulations (Installations & Use) 1996.
The Local Building Regulations.
The Building Regulations.
The Buildings Standards (Scotland - Consolidated) Regulations.
British Standards Codes of Practice:
B.S.
7593
1992
TREATMENT OF WATER IN DOMESTIC HOT WATER CENTRAL HEATING SYSTEMS
B.S.
5546
1990
INSTALLATION OF HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
B.S.
5440
PART 1 FLUES
B.S.
5440
PART 2 AIR SUPPLY
B.S.
5449
1990
FORCED CIRCULATION HOT WATER SYSTEMS
B.S.
6798
1987
INSTALLATION OF GAS FIRED HOT WATER BOILERS
B.S.
6891
1989
GAS INSTALLATIONS
B.S.
7671
1992
IEE WIRING REGULATIONS
B.S.
4814
1990
SPECIFICATION FOR EXPANSION VESSELS
B.S.
5482
1994
INSTALLATION OF LPG
Model Water Bye Laws
For Northern Ireland the rules in force apply
2. TECHNICAL AND DIMENSIONAL CHARACTERISTICS
2.01 Technical information
Falcon II boilers are central heating and domestic hot water heat generators and are produced as standard to function
with natural gas or liquid Petrolium Gas converted appliances.
Key
1 - 3/4" central heating flow outlet
2 - 1/2" domestic hot water flow outlet
733
460
430
85
14
362
200
720
Ø60
115
Ø100
75
189
Distance between connections
36
95
60
60
155
54
175
Bottom view
4
2
3
5
1
189
460
Top view
120
120
200
110
80
110
3 - 1/2 “ gas inlet
4 - 1/2" domestic hot water inlet
5 - 3/4" central heating return inlet
N.B. - The gas pressures at the burner and gas flows during the central heating phase given in the table refer to
nominal boiler output. To reduce this output (where necessary), gas pressure must be reduced until the required
output level is reached (see figures 4 and 5).
During domestic hot water production, gas pressures to the burner must correspond to the maximum output
given in table for the type of gas.
Gas pressure must be adjusted during maximum draw-off of domestic hot water.
• Maximum working temperature for central heating flow: 85°C
• Maximum temperature of domestic hot water: 55°C, adjustable between 40°C and 55°C.
• Minimuum domestic cold water pressure required for 95% heat input:
- Flow restrictor fitted (standard) - 1,2 bar;
- Flow restrictor removed - 0,5 bar
Technical Data
2.03 Boiler water flow diagram
2.02 Boiler main components
Key
5 Room sealed compartment
7 Gas inlet
8 Domestic hot water outlet
9 Domestic hot water inlet
10 Central heating flow outlet
11 Central heating return inlet
14 Safety valve
16 Fan
19 Combustion chamber
20 Burner assembly
21 Main injector
22 Burner
26 Combustion chamber insulation
27 Copper heat exchanger for central
heating and domestic hot water
28 Flue collector from heat exchanger
29 Internal flue exit
32 Central heating pump
34 Central heating flow temperature sensor
36 Automatic air vent valve
Fig. 2
Fig. 3
81
82
22
29
43
187
+
-
R
OVER RIDE
x
x
4
AUTO
P
O
I
P
IN
OUT
MIN
GRUNDFOS
FERROLI
114
34
20
21
90
50
16
28
32
26
19
49
132
5
56
27
91
62
10
8
7
84
85 44
136
14
42
9
11
36
98
63
157
145
0
5
1
2
3
4
6
OUT
I
MIN
AIR
IN
AIR
IN
FLUE
OUT
C.H.
OUT
D.H.W.
OUT
GAS
IN
D.H.W.
IN
C.H.
IN
42 Domestic hot water flow
temperature sensor
43 Air pressure switch
44 Gas valve
49 Safety overheat thermostat
50 Central heating flow limit thermostat
56 Expansion vessel
62 Time clock
63 Central heating temperature adjustment
81 Ignition electrode
82 Sensor electrode
84 Primary gas valve solenoid
85 Secondary gas valve solenoid
90* Flue outlet test point
91* Air test point
98 On/Off/Reset switch
114 Low water pressure cut off switch
132 Flue gas deflector
136 Flow meter
145 Central heating pressure gauge
157 Domestic hot water temperature adjustment
187 Restrictor
* For use with flue gas analyser
2.05 Pump characteristics
The pump head available for circulating the water
is given in fig. 6.
N.B. - The pump is factory set at position 3. The pump
is a Grundfos type 15-50 UPS series.
Grundfos Pump performance graph
Note - Minimum flow through boiler heat exchanger at
any time should not fall below 6 litres per minute.
If the total volume of water in the system exceeds 40
litres an additional expansion vessel must be fitted to the
central heating return pipe.
Pump performance curve Grundfos UPS 15-50
Fig. 6
1 2 3 Speed settings
A
Boilers pressure drop
B
Available pump head C.H.
2.04 Central heating adjustment (not normally required)
To adjust boiler heat input (thus also regulating heat output to the central heating water) simply adjust the main burner
via the electronic control board (fig. 4 and 5 and see paragraph 5.04 page 23).
The diagrams indicate the variation in heat output to the water as burner working pressure is varied.
Adjusting boiler output to the actual requirements of the central heating system will minimise boiler cycling thus saving fuel,
varying the output has virtually no effect on the efficiency and combustion characteristics of the boiler.
Diagram of pressures
and outputs with Natural gas
Fig. 4
Fig. 5
Diagram of pressures and outputs
with LPG (Propane)
2
3
4
5
6
7
8
9
10
11
12
13
12 13 14 15 16 17 18 19 20 21 22 23 24
11 12 13 14 15 16 17 18 19 20 21
kW
kcal/h
x 1000
mbar
14
25 26 27 28 29 30 31
22 23 24 25 26
kW
kcal/h
X 1000
mbar
18 19 20 21 22 23
5
10
15
20
25
30
35
12 13 14 15 16 17
11 12 13
14
18
19
20
15
16
17
25 26 27 28 29 30
24
21
25
26
22
23
24
SIZING OF ADDITIONAL EXPANSION VESSELS:
Deduct from the value given in the table the 10
litre vessel supplied.
Note:
1.
Fill C.H. installation to min. 1.5 bar.
2.
Expansion vessel must be fitted to central
heating return pipe.
3.
The standard 10 litre expansion vessel is
charged to 1 bar.
4.
The additional expansion vessel should be
charged to 1 bar.
SAFETY VALVE
SETTING (bar)
VESSEL CHARGE
PRESSURE (bar)
INITIAL SYSTEM
PRESSURE (bar)
TOTAL WATER
CONTENT of SYSTEM
3.0
0.5 1.0 1.5
1.0 1.5 2.0 1.5 2.0 2.0
EXPANSION VESSEL VOLUME (litres)
LITRES
25 3.5 6.5 13.7 4.7 10.3 8.3
50 7.0 12.9 27.5 9.5 20.6 16.5
75 10.5 19.4 41.3 14.2 30.9 24.8
100 14.0 25.9 55.1 19.0 41.2 33.1
125 17.5 32.4 68.9 23.7 51.5 41.3
150 21.0 38.8 82.6 28.5 61.8 49.6
175 24.5 45.3 96.4 33.2 72.1 57.9
200 28.0 51.8 110.2 38.0 82.4 66.2
0.140 0.259 0.551 0.190 0.412 0.33
For syst. volumes other than
those given above, mult. the syst.
volume by the factor across
Fig. 7
Pressure loss diagram
m |h
3
Q
8
7
6
5
4
3
2
1
0
0.5
1.5
2.5
1
2
H
mbar x 100
3.0 INSTALLATION DETAILS
Gas Safety (Installation & Use) Regulations: 1996
In the interest of safety, it is the law that all gas appliances are installed by a competent person in accordance with the
above Regulations, Building Regulations/Building Standards Scotland, Codes of Practice, current I.E.E. Regulations and
the byelaws of the Local Water Undertaking. Failure to comply with the Regulations may lead to prosecution; it is your
responsibility to ensure that the law is complied with.
N.B. For Northern Ireland the rules in force apply.
Important - If the boiler is to be fitted in a timber framed building it should be fitted in accordance with the Institute of Gas
Engineers document IGE/UP/7. If in doubt advice should be sought from the Local Supplier.
Location of Boiler
The installation of the Falcon II must be on a suitable non-combustible load bearing wall which will provide an adequate
fixing for the boiler mounting bracket assembly. The location should be in an area where the water pipes will not be
subjected to frost conditions. In siting the combination boiler the following limitations must be observed:
The combination boiler may be installed in any room or internal space, although particular attention is drawn
to the requirements of the current I.E.E. wiring regulations and in Scotland the electrical provisions of the
building regulations applicable in Scotland, with respect to the installation of the combination boiler in a room
or internal space containing a bath or shower.
Where a room sealed appliance is installed in a room containing a bath or shower any electrical switch or appliance control
utilising mains electricity must be situated so that it cannot be touched by a person using the bath or shower.
Air Supply
The room or compartment in which the boiler is installed does not require a purpose provided vent when
using the standard concentric flue.
Flue System
The boiler allows the flue outlet to be taken from the rear of the boiler, from either side or vertically.
A standard flue length of 0.75 metres is provided. Alternative lengths of two or three metres can be supplied (equivalent
to wall thicknesses of up to 565, 1815 and 2815mm for rear flues, deduct 91mm plus distance from side wall for
side outlet flues). It is absolutely essential, to ensure that products of combustion discharging from the terminal
cannot re-enter the building, or enter any adjacent building, through ventilations, windows, doors, natural air
infiltration or forced ventilation/air conditioning.
Gas Supply
If necessary the local Gas supplier should be consulted, at the installation planning stage, in order to establish
the availability of an adequate supply of gas.
An existing service pipe must not be used without prior consultation with the Local Gas supplier.
A gas meter can only be connected by the Local Gas supplier, or by a Local Gas suppliers Contractor.
Installation pipes should be fitted in accordance with BS6891-1988.
Appliance inlet working pressure must be 20mbar MINIMUM, for NG and 37 mbar minimum for LPG.
Pipework from the meter to the combination boiler must be of an adequate size.
The boiler requires 3.5 m3/h of natural gas, and 2.60 kg/h of LPG.
Do not use pipes of a smaller size than the combination boiler inlet gas connection.
The complete installation must be tested for gas soundness and purged as described in BS6981-1988. All pipework
must be adequately supported. An isolating gas valve is provided and should be fitted on the boiler gas inlet. Please
wait 10 minutes when lighting from cold before checking gas rate. Gas pressures should be checked after the boiler has
operated for 10 minutes to reach thermal equilibrium.
Water System
Note - the boiler is designed for sealed systems only and must NOT be used on open vented systems.
Detailed recommendations are given in BS6798, BS5449, BS6700 and CP342 Part 2. Pipework not forming part of the
useful heating suface should be insulated to prevent any heat losses or possible freezing (i.e. in roof spaces or ventilated
underfloor spaces). Drain taps should be positioned at the lowest point of the system in accessible locations to permit
the whole system to be drained down. The drain taps should be in accordance with BS2879. Copper tubing to BS2871,
Part 1 is recommended for water carrying pipework. Pipework in horizontal runs should have a gradient where possible
to facilitate the removal of air. Ensure that the boiler heat exchanger is not a natural point for air collection. A typical
heating system with domestic hot water circuit is illustrated in fig. 8.
Important - If thermostatic radiator vales are fitted a bypass must be fitted to ensure a minimum flow rate through the
boiler of 6 l/min. The bypass should be fitted as far as possible from the boiler.
Make Up Water
Provision must be made for replacing water lost from the sealed system. Reference should be made to BS6798,
for methods of filling and making up sealed systems. There must be no direct connection between the boiler's
central heating system and the mains water supply. The use of mains water to charge and pressurise the system
directly, is conditional upon the Local Water Byelaws. Again any such connection must be disconnected after use.
A typical temporary filling loop is shown in fig. 9.
Domestic Hot Water
Always fit a scale reducer in "hard water areas" (18 clarke degrees or over)". A 15mm copper connection point on the
boiler for attaching to the main supply is provided. The maximum domestic water pressure for the inlet supply is 10 bar (145
P.S.I.). If the cold mains supply exceeds 5 bar (72 P.S.I.), a water governor or pressure reducing valve must be fitted by
the installer into the mains supply in an inconspicuous but accessible position preferable between 3 and 5 metres (10-16ft)
before the appliance. Such a valve must be approved by the Water Research Council.
Attention - is drawn to the Model Water Byelaws.
Fittings manufactured from duplex (alpha-beta) brass are not acceptable for underground use and certain water
undertakings will not accept their use above ground.
Ensure all pipework is adequately supported
NOTE: A bypass must be fitted as far as possible from
the boiler if thermostatic radiator valves are fitted
thoughout.
Fig. 8
Gas
Cold water
Additional expansion vessel
C.H. (if required)
Filling
point C.H.
Bypass
Key
1. Filling point C.H.
2. Temporary connection
3. Cold water supply
Fig. 9
POSITION MINIMUM SPACING mm
A Directly below an openable window, air vent, or any other ventilation opening 300
B Below gutters, soil pipes or drainpipes 75
C Below Eaves 100
D Below a Balcony 100
E From vertical drainpipes or soilpipes 75
F From internal or external corners 100
G Above adjacent ground or balcony level 100
H From a surface facing the terminal 600
I Facing another terminal 1,200
J From opening (door/window) in carport into dwelling 1,200
K Vertically from a terminal on the same wall 300
L Horizontally from a terminal on the same wall 300
N Below carport 600
A Quinnel Barrat and Quinnel guard (part. No. C2) should be screwed to the wall centrally over the terminal, when
the terminal height is less than 2 m from floor level.
Fig. 11
CLEARANCES:
* 600mm minimum clearance for servi-
cing access
460
5 min.
5 min.
100 min.
852
200 min.
360
50 mm
600* min.
760
Fig. 10
3.01 Drilling Template (Top Flue Application)
Select suitable mounting position for boiler, using the template mark flue outlet and boiler mounting points. Drill two
10mm holes 90mm deep to accept the wall plugs, fit wall plugs. Fit two special wall plugs on the wall as described in
the fig. 12a. Fasten the wall bracket to the wall using an antitheft nut on the right side and a standard nut (M8) on the
left side. Mount the boiler on the wall bracket and fix using an antitheft nut on the left side and a standard nut (M8) on
the right side. Using a core drill cut a 118mm diameter hole for the flue.
1.
CH flow
2.
Safety Valve
3.
Domestic hot water outlet
4.
Gas supply
5.
Domestic hot water inlet
6.
CH return
Fig. 12b
75
5 min
195 min
200 min
955 min
200
460 min
1
2
3
4
5
6
15
15
Ø3/4''
Ø3/4''
Ø1/2''
Ø1/2''
Ø1/2''
Ø1/2''
=
=
Ø120
jig bracket
Fig. 12a
For boiler operation, the restrictor supplied with the unit must be mounted following the instructions below.
Determine the correct size of flue restrictor required. Before inserting the flue gas duct in the boiler, check that the
restrictor fitted is correct and that it is correctly positioned (see fig. 13).
N.B.: the diameter of the hole is stamped on
the restrictor
Boiler is fitted with Ø47 restrictor as
standard
Holes Ø : 47 50 52
Ø
Fig. 13
Choice of restrictor:
• With concentric pipes: - up to 1m long + one bend, use the 52 mm restrictor.
- for flue lengths over 1 metre, use no restrictor.
• With 2 pipe system: - Calculate the total flow resistance of the air and flue pipes in metres
(cap. 3.04.2)
- utilise the table shown below to choose the more suitable restrictor for
the flow resistance calculated
A 90° bend (fig. 15) is supplied for the horizontal connection of air and flue gas pipes. This can be angled
towards the chosen wall in degrees of 45°.
3.03 Top Outlet Concentric Flue Connection
3.03.1 Vertical concentric connection
1KWMA31Y
D
S
L
125
70
50*
30
95
80
80
-3 mm/m
Ø60
Ø80
70 min.
* = between 10 e 60 mm
190
270
Fig. 15
A vertical connector can be supplied for vertical discharge
with concentric pipes.
The simple mounting and use of double lip gaskets at the
joints makes this an extremely easy and safe option.
Fig. 14
Concentric
Vertical
Connector
3.03.2 Horizontal concentric connection
L = S = D = 255
1J7MA31Y
Notes on concentric horizontal installation
To locate the centre of the hole for passing the
pipes through the wall, refer to fig. 12. Bear in
mind that the two concentric pipes must slope
downwards away from the boiler at a rate of about
3 mm/m to avoid rainwater entering the boiler. The
concentric pipes making up the air - flue gas duct
must be sealed with the gasket where they join
the boiler (fig. 16). Outside, the pipes should
protrude from the wall between 10 and 60 mm
(fig. 16).
Between
10-60mm
3.03.3 Maximum concentric flue length
First table below shows the maximum flue lengths available for boilers with concentric systems.
For correct calculation remember to include the reduction for bends on second table. Please refer to 3.02
for use of restrictor
*For horizontal Flueing the reduction for appliance bend or turret are already included.
max. 3 m
max. 4 m
Fig. 17a
Fig. 17b
3.04 Top Outlet: Two Pipe Flue System
3.04.1 Two pipe connection
Two separate ducts Ø80 for air intake and flue gas
discharge can be directly connected to the boiler. mount
the separate outlet kit "1".
Insert blanking plate 2
in remaining air intake
Connect flue duct to central hole Ø80 and air duct to left or right air intake hole Ø80. Insert blanking plate
"2" in remaining air intake.
A varied selection of accessories for two pipe systems are available from FER (ref. to page 17). Before installing
your system please check via calculation table at 3.04.2 you are not exceeding the maximum permissible
length for the appliance.
IMPORTANT:
Notes on two pipe system installation:
When using the two pipe system the flue discharge pipe must have a 25mm air gap when passing through combustible
materials. Where the flue discharge pipe passes through the airing space of an airing cupboard it must be protected by a
non combustible guard or expanded metal giving an annular air gap of at least 25mm.
Where the flue discharge pipe passes through a wall containing cavity insulation, a non combustible sleeve must be
fitted. Additionally a gap of 25mm between the sleeve and the insulation should be provided by cutting back the insulation
or packing loose fill bead insulation with mineral fibre. Where the flue pipe is run through an unheated roof space it
should be insulated with non combustible insulating material to prevent condensation. The flue pipe should be supported
at intervals of not more than 1.8m and the support should be preferably below a joint.
3.04.2 Two pipe flue system
To determine the maximum length of flue and air pipe permissible.
The calculation is based on a standard reference resistance of 1 metre of 80 mm horizontal air intake pipe. For every
configuration of the two-pipe system all components will have a resistance factor based upon this reference. (I.e. a 90
degree bend fitted in the flue line would attract a resistance factor equivalent to 2.5 Metres of horizontal 80mm pipe).
This is expressed as X metres. Each boiler will have a maximum equivalent length of flue/air pipe and this is shown in
the table as N metres. Therefore when calculating the proposed flue run the equivalent resistance of every length of pipe
and every bend, whether air intake or flue discharge is added together to give an actual total flue length. The final figure
calculated must not exceed the permitted maximum length (N metres) for each boiler type.
Calculation Routine
1. Identify all the components needed to complete the proposed flue/air pipe run.
2. Calculate the sum of all the equivalent lengths (see table at next page).
3. For boilers, which may require a flue restrictor, refer to table at page 13 (par. 3.02) to ascertain the correct
size and add this resistance to your total.
4. Check and verify that the total flue/air pipe length (flow resistance) does not exceed 50 mt. maximum
permitted for Falcon II.
IMPORTANT: Resistance factors apply to standard férroli components only.
Male-female flue/Air pipe
1 m - Ø 80
Female-female bend
45° Ø 80 m
Male-female bend
90° Ø 80 m
Dscription
Horizontal
flue terminal
Ø 80 mm
Air intake
terminal
Ø 80 mm
Outlet flue/air inlet
for concentric system
Ø 100/60 mm
Pipe fitting for
outlet flue
Ø 80 mm
Outlet flue/air inlet
for connection
with split end
Ø 80 mm
1
1
1
2
1,2
2,2
1,5
2,5
REDUCTION
5
2
4
AIR
FLUE
Vertical
Horizontal
Vertical
Horizontal
REDUCTION
12
A
c
c
e
s
s
o
r
i
e
s
Ø
8
0
A
c
c
e
s
s
o
r
i
e
s
Ø
8
0
Spigot-and-socket
reduction Ø 100/80 mm
0
3.04.2 (continued)
Tab. 1 - Pipes and
fittings reduction table
For further accessories please refer to:
"Flue system manual for room sealed boiler"
Example of calculation for wall inlet/outlet
with 2 pipe system
maximum total flue length: 50 metres
Attention:
Remove the flue diaphragm.
The flue + air Pipes must have a 3% drop away from
the boiler to outside
7
6
3
2
5 1
13 m
13 m
Fig. 19
Example of wall inlet/outlet
2 pipe application
Example of roof inlet/outlet
Example of direct roof flue outlet
and wall air inlet
3.04.3 Example of other installation with two pipe systems
Fig. 20a
Fig. 20b
Fig. 20c
REF. N° OF PIECES DESCRIPTION LENGTH OR
REDUCTION
1 1 Air bend 80 mm R/D = 0,75 1,5 m
2 13 Horizontal air pipe 13,0 m
3 1 Air wall terminal 2,0 m
5 1 Flue bend 80 mm R/D = 0,75 2,5 m
6 13 Horizontal flue 26,0 m
7 1 Air wall terminal outlet flue 5,0 m
TOTAL 50,0 m
3.05 Connecting the central heating and domestic hot water circuits
Connect to the relevant connections as indicated in fig. 1. Connect the pressure relief valve discharge pipe (15mm)
to the outside of the building, where possible over a drain. The discharge must be such that it will not be hazardous
to occupants and passers-by or cause damage to external electric components or wiring. The pipe should be directed
towards the wall. To ensure long life, the heating circuit should be correctly sized and fitted with all the controls necessary
to ensure correct functioning and operation. The differential between the boiler flow and return pipes should not be
more than 20°C. You are advised not to use the boiler with return temperatures of less than 50°C in order to prevent
patches of condensation forming, having a corrosive effect on boiler components.
3.06 Boiler water characteristics
If the water is harder than 18 clarke degrees, the water used should be treated to avoid possible scale in the
boiler caused by hard water or corrosion by aggressive water. It should be remembered that as a result of its
low thermal conductivity, even scale of just a few millimetres thick can lead to considerable overheating of the
boiler walls, resulting in serious problems.
IT IS ABSOLUTELY VITAL THAT THE WATER USED IS TREATED IN THE FOLLOWING CASES:
a) Extensive systems (containing large quantities of water);
b) Frequent additions of water to top-up the system;
c) Domestic hot water circuits
If the system requires partial or total emptying, you are recommended to refill it with treated water.
3.07 Filling
When cold, system pressure should be about 1 bar. If while running venting off of air dissolved in the water causes
the pressure of the central heating system to drop below 0.5 bar, the user must utilise a filling loop to bring it back
to the original value. During operation, water pressure in the boiler when hot should be about 1.5 - 2 bars. After
filling, always close and disconnect the filling loop.
Note - If there is a possibility of air pockets forming in certain points of the central heating system flow and return pipes,
you are recommended to fit an air vent valve at these points.
Note - When the boiler is installed below the level of the central heating a system, single check valve should be fitted
in the flow to prevent gravity circulation around the heating system.
3.08 Gas connection
Gas connection should be carried out using a rigid pipe.
The flow at the gas meter should be sufficient for the simultaneous use at full gas rate of all appliances connected to it.
Connect the gas supply to the boiler according to current regulations. The diameter of the gas tube leaving the boiler is not
the determining factor in choosing the diameter of the pipe between the appliance and the meter. This must be selected in
relation to length and pressure drop and in any instance should not be less than 22mm.
The whole of the gas installation including the meter should be inspected and tested for soundness and purged
in accordance with BS6891-1988.
N.B. - The filling loop will be fitted by the installer at the time of installing the system. It is NOT a part
of the boiler.
3.09 Electrical connection
The boiler must be connected to a single phase 230 V 50 Hz electricity supply with a 3 A max. fuse and a bipolar switch
with contact opening of at least 3 mm fitted between the boiler and the electricity supply. The boiler must always be
connected to an efficient earth installation. Under the electrical box, there is a 3 pole terminal block for connecting
the boiler to the mains (230 V 50 Hz) and a 2 pole board for connecting a room thermostat (RT). To connect, undo
the screws fixing the terminal block box and connect the wires, ensuring correct polarity of the terminals. It should be
noted that there is low voltage (24 V) between the room thermostat contacts.
When the boiler is connected to an electricity main, it is essential TO OBSERVE CORRECT POLARITIES (LIVE: brown
cable, NEUTRAL: blue cable, EARTH: yellow-green cable).
All wiring must conform to current I.E.E. regulations.
Note: If the power supply cable has to be replaced, use “0.75mm (24/0.20) heat resisting cable only to BS6500
with a maximum external diameter of 8 mm.
Note - When connecting a room thermostat or external timer, do not link the power supply of these devices
to the switching contacts. The switch contacts must be voltage free. Any mains powered devices must utilise
mains power solely to drive the timer motor.
Applying mains voltage to the switch contacts will irreparably damage the circuit board.
Although this boiler can also be used without a room thermostat, you are recommended to install one for
the following reasons:
Greater comfort conditions due to more accurate control of room temperature.
Greater energy savings.
3.10 Differential air pressure switch (fig. 2 - part 43)
The differential air pressure switch is a safety device which allows the main burner to ignite only after having verified
that the fan is working correctly. If the difference in pressure between the flue gas discharge pipe and the air intake
pipe is not at least equal to the minimum pressure switch calibration value, the pressure switch contacts do not close
and the gas valve is thus prevented from opening.
In addition, the electrical circuit of the boiler is designed so that if for any reason the air pressure switch contacts remain
closed when the fan stops, the burner will not start up again.
3.11 Checks
Fill the central heating system as described previously (3.07) and check there are no leaks in the domestic hot
water and boiler water circuits. Check that there are no gas leaks on the boiler or the supply to the boiler. Also
check that the electrical connections are correct.
3.12 Installing a room thermostat (72) (fig. 35 pag. 39)
To connect the thermostat:
Open the electrical box on the base of the appliance and remove the “jumper cable” between terminals 3 and 4.
Connect the room thermostat (72) as shown in figure 35.
4. COMMISSIONING AND TESTING
4.01 Checks to be carried out before starting up for the first time
When starting the boiler up for the first time check:
• that the gate valves between the boiler and central heating system are open;
• that the central heating system is filled and vented;
• that there are no gas or water leaks from the central heating system or boiler;
• that the electric connections are correct and the earth wire of the boiler is connected to an efficient earthing
installation and a 3amp. fuse is fitted to the isolator;
• that there are no flammable liquids or materials near the boiler;
4.02 Starting up the boiler
• Open the gas cock upstream of the boiler.
• Vent air present in the pipe upstream of the gas valve.
• Turn on the electrical supply to the boiler.
• Rotate the ON-OFF-Reset switch (fig. 2 - part 98) into the ON position.
• Check inlet working gas pressure, burner pressures and gas rate.
At this point, choose whether the boiler is to be used for central heating and domestic hot water production or for domestic
hot water production only. If the former is chosen (central heating and domestic hot water production), turn the knob 63 (fig.
2) to the “Winter” position. Set the knob above 50°C and set the room thermostat (if fitted) to maximum. The burner ignites
and the boiler starts to function automatically, controlled by its control and safety devices.
If the latter is chosen (domestic hot water production only), position the knob 63 (fig. 2) on the “Summer” position. In this
mode the boiler is ready to operate automatically whenever domestic hot water is drawn off.
Note - If after completing the start-up procedure correctly, the burners fail to ignite and the boiler shut down warning
lights up, wait about 15 seconds then rotate the knob 98 (fig. 2) against spring pressure to the RESET position and
release it. The reset electronic control unit will repeat the start-up cycle.
Note - In central heating mode after resetting the boiler will go into it 2 minute delay before starting up again. If after a
second attempt the burners still fail to ignite, consult the paragraph “Fault Finding” (pag. 31).
Note - If there is a power failure while the boiler is in operation, the burners automatically go out and re-ignite
when the power returns.
4.03 Shutting down
Close the boiler isolation gas cock and turn off the electricity to the boiler.
Important: If the boiler is not to be used for lengthy periods during the winter, to avoid frost damage, you are recommended
to drain the water from the circuits (domestic hot water and central heating). Alternatively, drain the domestic hot water
system only and add special anti-freeze to the central heating system.
4.04 Checks and controls after first start-up
• Check there are no leaks in the gas and water circuits.
• Check correct boiler start up by carrying out start up and shut down tests using the boiler stat.
• Check the integrity of the air-flue pipes during boiler operation.
• Check that the gas consumption indicated on the meter corresponds to that given in Technical Data (page 5).
• Check that water is circulating correctly. Balance the radiators to ensure that the flow and return differential
does not exceed 20°C.
• Check that when operating in the “Winter” mode, the pump stops and domestic hot water is produced correctly
when the hot water tap is turned on.
• Check that in the “Summer” mode, the burner lights up and shuts down correctly when the domestic hot
water tap is turned on and off.
5. ADJUSTMENT AND GAS CONVERSION
5.01 Adjusting the pressure and flow rate to the main burner
This boiler operates on the flame modulation principle. It has two fixed pressure values, minimum and maximum,
which must be as shown in the table (pages 5), whichever type of gas is used.
Note - Because correct minimum and maximum pressures are critical to the efficient operation of the boiler it is ESSENTIAL
that the following adjustments are carried out by COMPETENT personnel ONLY.
5.02 Adjusting minimum and maximum pressure Honeywell V K4105G gas valve
- Connect suitable pressure gauge to burner test point “B” downstream of the gas valve.
- Disconnect the pressure compensation tube «F».
- Remove the protective cap «C».
- Adjust potentiometre P3 (on the main board) at minimum
(anticlockwise).
- Operate boiler for central heating
- Adjust minimum pressure by rotating screw «D» clockwise to
reduce pressure and anticlockwise to increase pressure.
- If it is not possible to achieve the right pressure adjust minimum
pressure by potentiometer P5
- Adjust potentiometre P3 at maximum (clockwise)
- Adjust max pressure by rotating screw «E», clockwise to
increase pressure and anticlockwise to reduce pressure.
- Reconnect the pressure compensation tube «F».
- Replace protective cap «C».
Maximum + Minimum possible gas pressures are now set. Range
Rating the central heating is not necessary (see paragraph
5.04).
Fig. 21
IN
OUT
C
F
E B A
D
Legenda
A
=
Gas inlet test point
B
=
Gas outlet test point (burner pressure)
C
=
Protection cap
D
=
Min. pressure adjusting screw
E
=
Max. pressure adjusting screw
F
=
Balancing tube
• Check that the domestic hot water flow and T correspond to the table. Do not rely on empirical measurements.
Temperature should be measured using thermometers as near as possible to the boiler, bearing in mind
the heat loss from the pipes.
• Check that the gas valve modulates correctly both during the central heating phase and the domestic hot
water production phase.
• To determine combustion efficiency and the composition of the flue gases (refer to 6.04)
• If any of the above are not correct refer to Technical Data (page 5). Adjustment (refer to 5) and Fault
finding (page 31).
5.04 Adjusting maximum output for central heating system (fig. 22)
This adjustment must be carried out electronically using the “P3” adjustment screw starting with a cold central heating
system. Connect a pressure gauge to the pressure test point downstream of the gas valve. Rotate the temperature
adjustment screw to maximum then regulate the pressure to the value required, consulting the diagram (figs. 4 and 5).
Once this operation is complete, start up and shut down the burner two or three times using the thermostat. Check each
time that the pressure values remain as adjusted and that the burner ignites correctly. Otherwise further adjustment is
necessary until the pressure remains stable on this value.
N.B. - when carrying out this operation ensure that the boiler thermostat is set to maximum otherwise the
adjustment will not be accurate.
5.05 Adjusting central heating flow temperature
Central heating water temperature is adjusted by rotating the control knob (fig. 2 - part 63). Rotate the knob clockwise to
increase water temperature, anticlockwise to reduce water temperature. Temperature can be varied from a minimum of
30°C to a maximum of 85°C. However, we recommend not operating the boiler below 50°C.
5.06 Adjusting room temperature (when a room thermostat is fitted)
Room temperature is controlled by positioning the room thermostat knob to the required value. The thermostat automatically
controls the boiler, temporarily interrupting the electrical supply subject to the room heat requirements.
5.07 Adjusting the central heating flow t by varying pump flow-head
The thermal head t (the difference in temperature between the delivery water and return water in the central
heating circuit) must be less than 20° c. This is obtained by varying pump flow rate and head using the multi-speed
variator (or switch) on the pump itself. Increasing the pump speed reduces t and vice versa. The minimum
differential must not be less than 11°C.
5.08 Adjusting central heating system pressure
The pressure of water in the central heating system, read on the control panel pressure gauge, is adjusted as
described in paragraph 3.07.
N.B. - To avoid incurring unnecessary expense, in the event of boiler shut down, check that this is not caused by a lack of
electricity or gas, or low water pressure before calling the Customer Technical Service Helpline.
5.09 Gas conversion
The following adjustment and conversion operations must be carried out by competent personnel. FER Limited
accepts no liability for damage to property or personal injury resulting from tampering with the boiler by
unauthorised persons. To convert the boiler from Nat Gas to LPG and vice versa, the main burner injectors must
be replaced. Minimum and maximum pressures must then be adjusted on the gas valve (see Adjustment page
22). JP02 must be moved to the LPG position.
Note: After converting the boiler from natural gas to liquid gas, fit the orange plate in the conversion kit
near the data plate.
Fig. 22
5.03 Adjustment
potentiometers
P1 =
C.H. temperature adjustment
P2 =
D.H.W. temperature adjustment
P3 =
C.H. output adjustment
P4 =
Ignition gas pressure adjustment
P5 =
Minimum gas pressure adjustment
+
-
+
-
P2
DHW
+
-
P3
+
-
P5
+
-
P4
P1
CH
6. MAINTENANCE AND CLEANING
The following operations must be carried out by Corgi registered engineers only.
6.01 Annual Servicing
The following should be checked at least once a year:
• Water pressure in the central heating system when cold should be about 1 bar. If this is not the case, bring
it back to this value.
• Check control and safety devices (gas valve, flow meter, thermostats, etc) are functioning correctly.
• The burner and heat exchanger must be clean. To avoid damage, always clean them with a soft brush or compressed
air. Never use chemical products.
• The expansion vessel must be checked (precharge 1 bar).
• Check there are no leaks in the gas and water circuits.
• Check the air-flue gas duct terminal is free from obstructions and sound.
• The electrodes must be free from corrosion build up and correctly positioned.
• Gas flow and pressure must correspond to the values given in the Technical Data (page 5).
• The pump must be free to rotate.
6.02 Cleaning the boiler and burner
The boiler should be serviced annually. The heat exchanger and burner must never be cleaned with chemical products
or steel brushes. Particular attention must be paid to all seals and fixings associated with the room-sealed compartment
(gaskets, grommets, etc). Air leakage would cause pressure inside the compartment to drop, possibly tripping the
differential pressure switch and thus shutting down the boiler. After cleaning particular attention should also be paid to
checking stages of start-up and operation of the thermostats, gas valve and pump.
6.03 Servicing procedure
1. Visually check boiler for correct intallation and flueing.
2. Isolate electricity supply + check fuse is 3amp.
3. Remove case by undoing the two screws locate at the bottom rear corners, lift slightly and pull forward.
4. Carry out preliminary electrical checks at boiler junction box. This is located in the centre of the boiler
at the bottom and can be accessed be the removal of a single screw. Any faults found must be rectified
before proceeding.
5. If electrical checks prove O.K. replace cover and secure with screw.
6. Attach a manometer to the boiler gas inlet test point, turn on electricty and fire boiler for hot water, check inlet
pressure. This should be 20mbar minimum for NG and 37mbar for LPG. If this is not the case there is a supply
problem and this will need to be remedied.
7. If inlet pressure is O.K. shut down boiler and remove manometer from gas inlet pressure test point and attach it to
the boiler burner pressure test point. Reseal inlet pressure test point.
8. Fire boiler for hot water and check that the maximum pressure is 13.0mbar for NG and 35.5mbar for LPG. Turn off
tap. Turn P3 on the main circuit board to minimum and fixe the boiler for heating, check that the burner pressure
reads 2.5 mbar for NG and 7.0mbar for LPG. Turn P3 back to max position. Shut down boiler, remove manometer,
seal test point and re-attach modureg lead. If the pressures are not as specified they will need to be adjusted on
the gas valve(see page 22 - installation manual).
10. Remove fan by undoing the two fan securing screws tilt the front of the fan upwards to detach it from the securing
pin and withdraw it from the boiler, disconnect the wires and air pressure switch tubes.
11. Take off the combustion chamber cover by removing the three securing screws.
12. Lift off flue hood and flue baffle plate.
13. Pull off the ignition and flame rectification leads from their respective electrodes.
14. Undo the gas union in the centre of burner rail and take out the two securing screws. Remove the burner
rail and clean rail and injectors.
15. Remove two screws securing the burner assembly and remove the assembly. Clean burners.
16. Clean heat exchanger with a soft brush.
17. Re-assemble baffle, flue hood and fan assembly, secure with screws previously removed.
18. Refit burner assembly and burner rail.
19. Reconnect ignition and flame rectification leads.
20. Reconnect gas union and tighten.
21. Refit combustion chamber cover, secure with screws.
22. Examine seals on room sealed cover refit cover and secure with screws.
23. Turn on gas and electricity.
24. Fire boiler and check all gas joints for soundess.
25. Check flame picture and all controls for correct operation.
26. Check room sealed cover for leakage.
27. Check domestic water flow rate and temperature is within specifications.
28. Check operation of all safety cut off devices.
29. If a combustion analyser is to be used there are test points provided on the front of the room sealed cover. The
right hand grommet is for air and the left hand one is for flue gas. The boiler must reach operating temperature
before this test is carried out (normally 10-15 minutes). CO/CO2 ratio should not exceed 0.0080. Immediately
after servicing (0.0040 at any other time)
30. Refit case and secure with screws.
31. Leave boiler set to customers requirements.
6.04 Flue Gas Analysis
1. The appliance should be checked visually for obvious
defects.
2. After removing the jacket on the boiler there are two test
point, one for flue gas and the other for air.
3. Open the air and flue gas test points;
4. Introduce the probes as far as the retainer;
5. Turn on the hot water tap;
6. Turn the domestic hot water stat to maximum;
7. Allow the boiler to reach thermal equilibrium (10 -
15 min.);
8. Take reading;
9. The CO/CO2 ratio should be 0.0040 or below. If the
reading is above this then a full strip down service must
be carried out and the cause remedied.
10. Following a full strip down service and after reaching
thermal equilibrium the permissible reading is 0.008
or below.
N.B.:
To ensure correct readings the boiler must have
reached normal operating temperature. Testing the
boiler before thermal equilibrium has been attained
will give incorrect readings.
FLUE
AIR
Fig. 23
7.0 REPLACEMENT OF PARTS
7.01
Initial procedure
a) The boiler is cold, electricity supply is isolated, and the gas supply is turned off at the inlet of the boiler
b) For replacement of parts where water connections are broken, it will be necessary to isolate and drain either or
both the central heating or domestic hot water circuits of the boiler. The cold water mains inlet is isolated at the
inlet cock. The D.H.W. is drained by opening a hot tap.
The C.H. flow and return cocks are turned off at the isolation cocks. The C.H. is drained via the pressure
relief valve (twist about 1/3 of a turn).
c) Remove components following special notice below and replace in reverse order.
d) Ensure water and gas washers are in good condition.
7.02 Final procedure
• Re-open cocks and re-charge the system to about 1 bar, and vent boiler and radiators.
Re-charge to 1 bar if necessary.
• Upon completion of the work the following. Should be checked:
I) Gas soundness of all joints
II) Water soundness of all joints
III) The electricity supply.
IV) The pressure of the sealed system and top up where necessary.
7.03 To lower the control panel (fig. 24)
• Remove the two fixing screw (fig. 24) "A"
• Rotate down the front panel "B"
B
A
7.04 Remove and re-presurising
of C.H. expansion vessel (fig. 25)
• Refer to 7.01 a, b
• Isolate electricity and water supplies
• Remove outer case (two screws bottom rear corners)
• Loosen the "A" connections to expansion vessel
• Remove "B" screws and metal flange "C"
• Remove the expansion vessel from the top of the boiler
• Re-assemble in reverse order
• Re-pressure expansion vessel
(charge pressure 0,8-1 bar) through the valve "C"
• Ensure pressure relief value is open
(twist about 1/3 of a turn) when repressurizing
Fig. 25
B
C
A
Fig. 24
7.06 Air pressure switch (fig. 27)
• Isolate electricity
• Remove outer case (two screws bottom rear corners)
• Open room sealed department
• Remove the two screw "A" fixing air pressure switch
• Disconnect electrical leads "B"
• Remove pressure sensing tubes (white=D; Red=C)
• Note relevant positions of all connections and
replace in reverse order.
Fig. 27
Fig. 28
7.05
Gas valve (fig. 26)
• Isolate gas and electricity supplies
• Remove outer case (two screws bottom rear corners)
• Remove the two securing screws and lower control panel
• Disconnect electrical connections
from valve ("A")
• Disconnect plastic tube "C"
• Loosen the connection "D" on gas pipe and the gas
inlet connection of the boiler "E"
• Remove the two fixing screw "E" below gas valve
• Slide out gas valve
• Remove four fixing screw "F" on top of
the valve and disconnect the gas pipe
• Remove bottom connection from gas valve.
• Fit top + bottom gas connections to the
new gas valve and replace in reverse order
C.H. sensor
Water pressure switch
D.H.W. sensor
Safety valve
A
B
C
D
D
C
A
F
E
7.07
D.H.W. temperature sensor or Central Heating Temperature Sensor
(fig. 28)
• Isolate electricity and water supplies
• Remove outer case (two screws bottom rear corners)
• Remove the two securing screws and lower control panel
• Identify the sensor from figure 28
• Disconnect electrical connection to the sensor
• Drain the affected service either D.H.W. or C.H.
• Unscrew the sensor
• Replace in reverse order
7.08
Water Pressure Switch (fig. 28)
• Isolate electricity and water supplies
• Remove outer case (two screws bottom rear corners)
• Remove the two securing screws and lower control panel
• Identify the switch from figure 28
• Disconnect electrical connections + note positions to the switch
• Drain the boiler
• Unscrew the sensor
• Replace in reverse order
7.09
Safety Valve (fig. 28)
• Isolate electricity and water supplies
• Remove outer case (two screws bottom rear corners)
• Remove the two securing screws and lower control panel
• Identify valve from fig. 28
• Drain the boiler
• Release the outlet union to the valve and
undo the valve
union connection
• Remove the valve outlet fitting
• Replace in reverse order
Fig. 26
Removal of burner (fig. 29)
• Isolate gas and electricity supplies
• Remove outer case (two screws bottom rear
corners)
• Remove room sealed cover
• Disconnect ignition and flame rectification
leads "A"
• undo gas rail union "B"
• Undo two screws securing the burner assembly
to the boiler combustion chamber "D"
• Withdraw the burner assembly
7.11
Injectors (fig. 29)
• Proceed as 7.08
• Remove fixing screw "C" on both
sides of gas manifold
• Remove gas manifold
• Unscrew and remove injectors;
• Clear or change injectors
Fig. 29
7.12
Removal of fan (fig. 30)
• Isolate gas and electricity supplies
• Remove outer case (two screws bottom rear
corners)
• Remove room sealed cover
• Disconnect fan electrical leads "A"and note
positions
• Disconnect air pressure tubes from air pressure
switch "B" + note positions
• Undo two screws securing fan assembly "C"
• Remove fan from boiler
• Swap mounting plate over to new fan + replace
in reverse order
7.13
Limit thermostat, or overheat
cut off thermostat (fig. 30)
• Isolate electricity
• Remove outer case (two screws bottom rear
corners)
• Remove room sealed cover
• Identify the location of thermostat from fig. 30
• Pull out thermostat from tube, with its spring
• Remove electrical connections from thermostat
• Remove spring from thermostat
• Replace in reverse order
Fig. 30
C
A
B
D
D
Overheat cut off thermostat
Limit thermostat
C
A
B
Spark or flame detection electrode
(fig. 31)
• Isolate gas and electricity supply
• Remove outer case (two screws bottom rear corners)
• Open room sealed compartment and combustion
chamber
• Identify electrode from fig. 31
• Unplug electrical connection "A" from sensing
electrode
• Remove fixing screw and remove flame detection
electrode
• Remove the two fixing screw from spark electrode
plate and remove it.
7.15
D.H.W. flowmeter
• Isolate electricity and water supplies
• Open a hot water tap to release water
pressure from the domestic side of
the heat exchanger, close tap.
• Remove outer case (two screws bottom rear
corners).
• Remove two screws from control panel and tilt
forward
• Take off protective cover from main PCB and
unplug flow meter lead from terminal X6
• Place a piece of cloth or some other absorbent
material over rear of control panel to catch
any drops of water that may be released when
removing the flow meter
• Using a 24mm open ended spanner, undo flow
meter unions "A" and "B" taking care not to twist
the copper tubing (access through base panel).
• Remove flow meter, check + clean filter +
restrictor + fit to new flow meter.
• Reassemble in reverse order.
Fig. 31
Fig. 32a
37
39
38
38
Key
37
Cold water inlet filter
38
Gasket
39
Cold water flow limiter
A
B
Spark
A
Flame
detect
Take care on correct position of
components as reported in fig. 32b
Fig. 32b
Pump (fig. 33)
Replacement of pump head
• Isolate electricity and flow and return pipes
• Remove casing (two screws bottom rear corners).
• Remove the two securing screws and lower control
panel
• Release pressure from boiler via pressure relief valve
• Unplug the pump lead "A" from the pump head
• Place a piece of cloth or other absorbent material over the
rear of the control panel to catch any drops of water that
may fall when the pump head is removed.
• Using a 4mm allen wrench undo the four allen screws
"B" in the pump head, lift away pump head from the
pump body
• fit new head into pump body and secure with the allen
screws tightening evenly.
• Replace electrical connection.
Replacement of pump body (fig. 33)
• Proceed as for removal of pump head
• Disconnect the expansion vessel connecting pipe "E"
from the rear of the pump body by removing the U clip
from the left hand side
• Disconnect the boiler return pipe and disengage the pump
lower connection by removing the U clip "C"
• Disconnect the pump to heat exchanger connection by
removing the U clip "F"
• Unscrew the two screws on bottom of pump "D"
• Turn the pump body through 90°, pull the bottom forward
and withdraw the pump body
• Reassemble in reverse order taking care to ensure the
O-rings are in place and undamaged.
Fig. 33
7.17 Removal of heat exchanger
• Isolate gas, water and electricity supplies
• Remove casing (2 screws bottom corners)
• Remove the two securing screws and lower control panel
• Drain heat exchanger for both CH + DHW
• Remove sealed compartment front panel
• Disconnect the overheat thermostat and central heating limit thermostat
• Remove the main burner, fan, flue hood and flow meter as described previously
• Remove the pump to heat exchanger flow connection and locknut
• Undo the domestic water outlet connection and locknut
• Lift out heat exchanger
• Re-assemble in reverse order
C
B
D
F
E
A
8.0 FAULT FINDING
Before beginning any fault finding ensure that gas, water and electricity are available.
WARNING: DO NOT link any terminals on block X10 or X11 as this will damage the PCB beyond repair.
8.01 Operating Sequence
With the power established the boiler is in its stand-by mode i. e. power on but no demand. The operational
sequence for C.H. and D.H.W. are as follows:
Central Heating Mode
External Call for Heat: The temperature regulator, built in or remote clock and room thermostat, if fitted, must
all call for heat. This will cause the pump to run.
Internal Call for Heat: C.H. flow temperature sensor, 88°C high limit and low water pressure switch all calling for heat.
If both external and internal calls for heat are present the MF03 PCB will energise.
In demand the fan will go to high speed causing the air pressure switch to operate. If the overheat (100°C) stat is closed
circuit the ignition will operate and the gas valve will be energised.
The burner will light at ignition burner pressure, automatically range rating itself up to the heating load, then
modulating down when the boiler reaches the desired flow temperature. When the central heating is satisfied the burner
will go off and the fan stops i.e. stand-by mode.
Note - If the boiler thermostat is set to maximum than the burner pressure will go to maximum effectively
bypassing the auto range rating facility
Domestic Hot Water Mode
External Call for D.H.W: Flow meter registers at least 2.5 litres/min flow to the hot water taps.
Internal Call for D.H.W: Hot water flow temperature sensor 88°C high limit stat and low water pressure
switch calling for heat.
If both internal and external calls are present the boiler follows the same sequence as for C.H. to light the burner. However,
for D.H.W. the burner will go straight to maximum and then modulate once the water reaches the set temperature of
the control thermostat. Turning the tap off will return the boiler to stand-by mode.
Note: Following shut down of the D.H.W. or C.H. the boiler will go into a three minute central heating delay.
8.02 Limit thermostats
T/Stat Location Function Nominal Circuit Wiring
Operating Colours
Temperature
C.H. Limit Top RHS Shuts downmain 88°C Low voltage Blue
of Heat burner if boiler DC Brown
Exchanger thermostat fails
Frost Incorporated Fires the boiler 7°C - 14°C Low voltage Red
in C.H. and runs pump to DC Red
Sensor maintain minimum
water temperature
Overheat Top LHS Protect boiler by 100°C 240V AC Brown
of Heat stopping ignition Blue
Exchanger and cuts power
to gas valve
The MFO3 PCB has fivediagnostic lights, each light corresponds to a particular function and will light in turn as
the boiler goes though its sequence of operations.
In order, the five lights indicate:
1 Boiler On Indicate
2 Boiler Shut down warning
3 Domestic Hot Water circuit ON
4 Central Heating standby (Flashing Light)
Central Heating circuit ON (Permanent Light)
5 Insufficient pressure in Central Heating System (Flashing Light)
Electric power supply ON (Permanent Light)
Note: Always check for sufficient gas supply (20mbar inlet working pressure for NG and 37mbar for LPG).
Minimum of 22 mm diameter pipework on C.H. flow and return with adequate by-pass. A correctly installed
flue system and a 3 amp fuse.
8.03 MF03 PCB
When operating the C.H. the following lights should be on: 4, 5 and flame on light. For D.H.W. the following
lights should be on: 3, 5 and flame on light.
If the boiler works for C.H. but not D.H.W., or vice versa, a number of components must be functioning and
can, therefore, be eliminated as being at fault.
Boiler will not light for D.H.W.
If boiler works for C.H. but not for D.H.W. the fault is most likely to be the flow meter or D.H.W. sensor.
If the tap symbol light is on the fault is the D.H.W. sensor. If this light is not on then suspect the flow meter
has not operated.
Boiler will not light for C.H.
If the boiler works for D.H.W. but not for heating the fault is most likely to be external controls (i.e. clocks or room
thermostats). Integral clock if fitted or C.H. sensor.
If the heating demand light is on the fault is most likely the C.H. sensor. If this light is not on suspect either
a clock or room thermostat not calling.
To override/eliminate any external controls disconnect them from terminal 3 and 4 underneath the boiler and
refit the link wire (see fig. 35 page 39).
Boiler will not light for D.H.W. or C.H.
The fault is likely to be a component common to both services. Open a hot tap to create a demand - is there
a spark at the ignition electrode?
Yes Suspect gas supply, pressure or gas valve.
No Is fan running?
Yes Suspect air pressure switch or overheat stat (if boiler locks out without sparking go to overheat stat)
No Is low water pressure light Flashing?
Yes Top up water to above 1 bar. Does the light go out? (if water pressure o/k suspect high limit stat)
Yes Does fan start?
Yes Does boiler light?
Yes Is hot water OK?
Try heating, if heating does not work follow guide for heating faults. Does low water pressure light go out?
No Suspect low water pressure switch.
If boiler still does not fire see comprehensive fault finding chart.
8.04 Temperature sensors (thermistors)
Identical, but individual, negative temperature co-efficient (NTC) thermistors are fitted in the C.H. and D.H.W. outlets
from the heat exchanger. As the water temperature increases the resistance in the thermistor decreases. This causes the
PCB to reduce the voltage to the modureg, in turn reducing the burner pressure. The wiring for each thermistor is colour
coded red for C.H. and blue for D.H.W. The sensors are fitted in wet pockets.
8.05 Limit thermostats
Two surface mounted auto reset bi-metal thermostats are located on the heat exchanger secured by spring
clips. Heat sink compound is used.
8.06 Ignition PCB
Located to the right hand side of the electrical control compartment accessed by lowering the facia then
removing the rear cover.
8.07 Main printed circuit board
Secured by three screws, the PCB is situated inside the control compartment. The transformer for low voltage AC is
attached to the PCB as is the DC rectifier. Potentiometers control C.H. output and maximum D.H.W. temperature, both
are adjustable by the controls on the facia and because the boiler features automatic range rating no adjustments need
to be made. Electro mechanical relays control pump operation and put switched live to the ignition PCB (demand relay),
they have transparent plastic covers so that their contacts can be seen moving.
8.08 Air pressure switch
Operating at 230 V AC and situated next to the fan. Different coloured tubes connect the switch to the fan. It is a make
on pressure switch and only uses two terminals, the middle terminal is not used.
8.09 Short spares list
KEY NO. DESCRIPTION PART NO. G.C. NO.
(from fig 2 )
14 Safety Valve 800130 386-816
16 Fan 800480 E23-851
34 Central Heating Flow Temperature Sensor 800320 E23-839
39 Cold water flow limiter
42 Domestic Hot Water Flow Temperature
Sensor 800320 E23-839
43 Air Pressure Switch 800150 E23-840
44 Honeywell Gas Valve 800266 E23-768
49 Overheat Safety Thermostat 100°C 801270 386-815
50 High Limit Thermostat 88°C 800160 386-577
81 Ignition Electrode °/N fixing Bracket 806460
82 Flame Sensing Electrode 801438 E23-855
136 Flow Meter 803430 E03-340
Main PCB MF03
27 Heat Exchanger 802180 E23-919
8.10 General test and fault finding
Chart 1
Check electrical supply - C.H. water pressure and frost protection
Is LED5 on?
Put main switch to on
CH Selector to
Summer “
” position
D.H.W. taps closed
Is 230V present across
terminals X1-1 X1-2?
Check and if necessary
replace 2A fuse
YES
Is LED5 ON now?
Repair external
wiring fault
NO
NO
Replace
main board
NO
YES
Is LED5 flashing?
YES
Water pressure
is not set
between
1 - 1,5 bar?
YES
Set pressure to
1 - 1,5 bar
Check water
pressure
switch wiring
connection
NO
Does fan run at full speed?
NO
Go to CHART 2
NO
YES
Does CH Pump run?
If the boiler temperature
is less than 5ϒC
frost protection is activated
Disconnect
CH flowtemp sensor
Has fan speed stopped?
Check and if necessary
replace main board
NO
YES
YES
Check and if
necessary
replace water
pressure switch
Chek the following carefully before starting
• Gas supply is turned on, is adequate and purged
• Electricity supply is turned on
• Polarity is correct
• CH pressure is set between 1 - 1,5 bar
• CH pump spins freely
YES
Is Relay RY101 switch on?
Check and if
necessary
replace pump
YES
NO
Check pump
wiring
connection
NO
Go to CHART 2
Check Domestic Hot Water operation
Wait 2 minutes
DHW taps closed
Put CH temperature selector
to maximum
Ensure external controls
are calling for heat
Is LED4 flashing?
Does C.H. pump run?
YES
YES
Go to chart 4
Is relay RY101
switch on
Check and if
necessary replace
main board
NO
Is LED4 flashing?
YES
NO
Is relay RY100
switch on
NO
YES
Go to chart 4
NO
Check
limit thermostat
YES
Check pump
wiring
connection
Check and if necessary
replace DHW Sensor
NO
Is LED3 on?
Open DHW taps
DHW flow rate at
least 2,5 litre/min?
Check cold water
inlet pressure
Check and if necessary
replace Flow Sensor
Is LED4 flashing?
NO
Is relay RY100 switch on?
NO
YES
Check if water
filter is clean
NO
YES
YES
YES
Check and if necessary
replace main board
Check and if necessary
replace limit thermostat
Go to
chart 4
NO
Check and if
necessary
replace pump
Chart 3
Check Central Heating operation
Wait 2 minutes
DHW taps closed
Put CH temperature selector
to maximum
Ensure external controls
are calling for heat
Is LED4 flashing?
Does C.H. pump run?
YES
YES
Go to chart 4
Is relay RY101
switch on
Check and if
necessary replace
main board
NO
Is LED4 flashing?
Check and if is necessary
replace main board
YES
NO
Is relay RY100
switch on
NO
YES
Go to chart 4
NO
Check
limit thermostat
YES
Check pump
wiring
connection
Check and if necessary
replace DHW Sensor
NO
Is LED3 on?
Open DHW taps
DHW flow rate at
least 2,5 litre/min?
Check cold water
inlet pressure
Check and if necessary
replace Flow Sensor
Is LED4 flashing?
NO
Is relay RY100 switch on?
NO
YES
Check if water
filter is clean
NO
YES
YES
YES
Check and if necessary
replace main board
Check and if necessary
replace limit thermostat
Go to
chart 4
NO
Check and if
necessary
replace pump
Check fan/flue gas system
Does fan run?
Is relay RY100 switch ON?
NO
Go to charts 2-3
NO
Is 230V present across
fan terminals?
YES
Check air pressure
switch wiring connection in N.O.
NO
Check and if
necessary replace
air pressure switch
NO
Check and if
necessary replace fan
YES
Is air pressure switch
activated?
YES
NO
Check and if
necessary replace
air pressure switch
YES
Differential air pressure
across the air pressure
switch is greater than
180 Pascal?
Go to chart 5
YES
NO
Check and clean fan
Check flue and air
intake are correct
and clean
Check Venturi and
air pressure switch
tubes are clean
Check restrictor
is correct
Chart 5
Check D.H.W. and C.H. modulation
Does burner
flame modulate?
Normal operation
carry out
YES
NO
Boiler operated
on central heating mode
Does burner
flame modulate?
Normal operation
carry out
YES
NO
Boiler operated
on DHW mode
Check CH sensor
and replace it if necessary
Check DHW sensor
and replace it if necessary
Check ignition system
Is LED1 light on?
Does sparking start
at burner?
Does burner light?
YES
Is LED2 on
after 10 seconds?
NO
YES
Go to chart 5
Reset lockout
YES
Does burner light now?
Is flame present before
lockout condition?
NO
YES
NO
Check and if necessary
replace safety thermostat
Check electrodes and
leads for damage
and correct connection
Check and if necessary
replace P.C.B.
Adjust with P4 ignition
burner pressure
Check and if necessary
clean burner
Check and if necessary
clean injectors
Check and if necessary
clean flame electrode
Check right position
of spark electrode
Check wires
Check gas supply
is live and purged
Check and if necessary
replace gas valve
NO
YES
Check and if necessary
replace P.C.B.
NO
Is LED2 on
without
the boiler sparking
YES
NO
Re-check
air pressure switch
JP01 ON = Delay between shutdown and re-ignition disabled
JP01 OFF = Delay between shutdown and re-ignition enabled
JP02:
Jumper on for natural gas
Jumper on for LPG
JP03 ON = Max temperature D.H.W. 62°C
JP03 OFF= Max temperature D.H.W. 55°C (standard)
Potentiometer adjustment
P1 = Central heating flow temperature adjustment
P2 = Domestic hot water temperature adjustment
P3 = Central heating flow output adjustment
P4 = Ignition gas pressure adjustment
P5 = Minimum adjustment pressure
9. ELECTRICAL AND FUNCTIONAL SCHEME
9.01 Main components layout on electronic boards
temp. Ohm
10 °C 20 kOhm
25 °C 10 kOhm
60 °C 2,5 kOhm
80 °C 1,25 kOhm
Temp.
sensor
NTC
(34) (42)
Fig. 34
X6
X1
X2
X3
X4
1
2
1
2
1
3
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
11
12
13
2
1
X5
L1
L2
L3
L4
L5
+
-
+
-
Transformer
P2
DHW
X12
1
2
+
-
P3
+
-
P5
+
-
P4
JP02
JP01
JP03
1
2
3
4
5
6
7
8
9
X10
Nat/LPG
P1
CH
X11
RY100
RY101
PC
PNO
L
N
HL
HL
MV1
MV2
MV3
MV4
FAN
L
N
X8
X7
MF03F
32 Central heating pump
34 Central heating flow temperature sensor
42 Domestic hot water flow temperature sensor
43 Air pressure switch
44 Gas valve
49 Safety thermostat
50 Central heating limit thermostat
62 Time clock
72 Room thermostat
Fig. 35
Key
BR Brown
BLUE Blue
BL Black
W White
O Orange
G Green
R Red
V Violet
IMPORTANT
USE A ROOM THERMOSTAT (24 V)
WITHOUT VOLTAGE TO THE CONTACTS.
CONNECTING 230 V TO THE ROOM
THERMOSTAT TERMINALS WILL
IRREPARABLY DAMAGE THE ELECTRONIC
BOARD.
81 Ignition electrode
82 Sensor electrode
98 Off/On/Reset switch
114 Low water pressure switch
136 Flow meter
9.02 General wiring diagram
X6
X1
X2
X3
X4
1
2
1
2
1
3
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
11
12
13
2
1
X5
TEST
-
+
X12
1
2
1
2
3
4
5
6
7
8
9
X10
W
O
V
R
X8
X7
81
82
MF03F
JP02
JP01
JP03
Nat/LPG
X11
230V
24V
230V
24V
BR
Blue
BR
Blue
BR
Blue
MV1
MV2
MV3
MV4
Blue
BR
Blue
BR
BR
Blue
R
R
Blue
Blue
O
O
Blue
BR
G
W
R
BL
BL
BL
Y/G
Y/G
BL
98
136
50
114
42
34
32
44
49
16
43
230V
50Hz
72
4
3
3
5
2
1
M
62
10. USER INSTRUCTIONS
The boiler is designed for use with two types of gas: natural gas NG or propane (LPG). The type of gas can be selected
when purchasing the boiler or the appliance can be converted later on site by a competent person. It operates with
technologically advanced systems such as electronic control, safety and control devices.
The boiler is fitted with automatic electronic ignition so there is no pilot to worry about.
Pull down cover to reveal control facia panel.
Make sure that the gas, water and electricity supplies to the boiler are turned on.
The boiler pressure gauge (D) should read at least 1 bar.
Low pressure will be indicated by flashing light in the middle of the facia illuminating (
).
Hot Water Only - “SUMMER” (
)
To obtain hot water only from the boiler, turn switch (A) to the on position. The top green light on the left side of
the control panel is illuminated (power on
).
Turn the temperature regulator (B) to the
position. Open a hot water tap, green light (tap symbol) comes
on, fan starts and burner will light. Indicated by flame symbol, green light coming on. The temperature of
the hot water can be adjusted by turning the hot water thermostat (C) clockwise to increase and anti-clockwise
to decrease the water temperature.
Heating and Hot Water - "WINTER” (
)
To obtain heating from the boiler, turn the temperature regulator (B) clockwise to the maximum position, ensure that
any other heating controls e.g. room thermostats, clock etc. are in the on position.
The boiler may be in heating delay of three minutes as indicated by the red light (egg timer symbol) on the left of the
facia panel. When this light goes out the green light (radiator symbol) will come on. The fan and pump will run and
the burner will light indicated by the green flame symbol light. Adjust the temperature regulator to the desired setting.
(In winter do not run boiler below 50°C). If a hot water tap is opened whilst the boiler is running for heating the pump
will stop, suspending the heating phase and the boiler will give priority to hot water production. When the tap is closed
the boiler will go into a three minute delay cycle before resuming for heating.
KEY
DESCRIPTION
A
Switch OFF/ON/RESET
B
Central heating flow
temperature regulation
C
D.H.W. temperature
regulation
D
Water pressure gauge
E
Time clock
+
-
R
OVER RIDE
12:31
x
x
4
AUTO
P
O
I
P
bar
A
B
C
D
Burner on indicator
Boiler shut down warning
Domestic hot water circuit on
Central heating stand-by (Flashing light)
Central heating circuit on (Permanent light)
Insufficient pressure in central heating system (Flashing light)
Electric power supply (Permanent light)
1
2
3
4
5
1
2
3
4
5
LED
E
0
5
1
2
3
4
6
In cold weather the boiler may appear to run when there is no demand for heating (i.e. clocks or room thermostats
turned off). This is due to the central heating sensor going into frost protection mode. Once the boiler has
reached 14°C or more it will close down until either the temperature again falls below 7°C or the clock or
room thermostat is turned on.
For this reason we recommend that the electricity to the boiler is left turned on. If you wish to turn off the electricity to
the boiler in winter you should drain completely the heating and hot water circuits.
Cleaning
The casing requires no special cleaning, a wipe with a soft duster or damp cloth will suffice.
Maintenance
Férroli recommend that the appliance is serviced at least once every twelve months by a competent engineer.
Gas Supply
It is the law that all gas appliances are installed and serviced by a competent person in accordance with the
Gas Safety Regulations (Installation & Use) 1996, and the manufacturers instructions. Failure to observe these
requirements may lead to prosecution.
Electrical Supply
WARNING - This appliance must be earthed.
The electrical wiring must be carried out by a competent electrician.
The colours of the wires in the mains lead of this appliance may not correspond with the coloured markings identifying
the terminal in the plug. Therefore, proceed as follows:
The wire coloured green and yellow must be connected to the terminal in the plug marked with either the letter E
or by the earth symbol or coloured green or green and yellow. The wire coloured blue must be connected to the
terminal marked either with the letter N or coloured black. The wire coloured brown must be connected to the
terminal marked either with the letter L or coloured red.
MINIMUM CLEARANCE
The minimum clearance around the appliance should be as follows:
Sides 5mm
Front 600mm
Below 200mm
Above 100mm
Boiler lock out
In the event of the red lockout light (
) coming on, the on/off/reset switch (A) should be turned clockwise against the
spring tension to the reset position and released (this will put the boiler into three minute delay if in the heating mode). If
the lockout light (
) illuminates repeatedly, contact an approved Férroli service engineer.
A 24 hour time clock is fitted to the boiler to control the central heating, this will come into operation when the selector
switch is turned to the position marked “heating timed and hot water”.
AUTO
+
-
R
OVER RIDE
x
x
4
A
B
E
R
D
P
AUTO
P
O
I
F
P
To set time of day
1.
Slide switch (A) to left position
2.
Using button + and - adjust until the correct time is shown on display (B).
Pre Set Programmes. The timer is pre programmed with 3 ON and 3 OFF times.
6:30 - 8:30
12:00 - 12:00
16:30 : 22:30
If these are suitable no programming is required and the slide switch (A) can be moved to the Auto
position and the central heating will be ON for these periods.
(12:00 - 12:00 will not switch on the boiler)
A Slide switch: set clock - auto - set programme
B Display. Symbol in Display = Timer ON
P Select programme ON/OFF 1.....8
D Push buttons Time + Time -
E Override: Boiler will switch ON if boiler is OFF; and OFF if is ON
F I=Heating continuous - AUTO=Heating timed - O=Heating disabled
R Reset (with pencil) only with switch A in set clock position
x
1.1 Use buttons + and - to set 1st ON time eg. 6:00
Display
2.1 Use buttons + and - to set OFF time, eg. 9:00
Display
3.1 Use button + and - to set 2nd ON time, eg. 12:30
Display
4.1 Use button + and - to set 2nd OFF time eg. 14:00
Display
5.1 Use button + and - to set 3rd ON time, eg. 16:00
Display
6.1 Use button + and - to set 3rd OFF time eg. 23:30
Display
8. On completion of programming slide switch (A) to Auto position,
the time of day will be displayed and the central heating will
switch ON and OFF according to the programme set.
1. Slide switch (A) to right position (P)
Display
2. Press button (P)
Display
3. Press button (P)
Display
4. Press button (P)
Display
5. Press button (P)
Display
6. Press button (P)
Display
7. The timer can be programmed with up to 8 ON and
8 OFF times by repeating the above procedure.
8:30 2
6:30 1
12:00 3
x
x
12:00 4
6:00 1
x
9:00 2
12:30 3
x
x
14:00 4
16:30 5
x
22:30 6
16:00 5
x
23:30 6
To Set Own ON and OFF times. Symbol in Display = ON time
Over ride
By pressing the over ride button (E) the timer programme is over ridden ie, if programme is in OFF time it will come ON
and if in ON time will go OFF. The timer will revert back to it set programme on reaching the next ON or OFF time.
When the programme is on over ride the sign will be shown in the display window (B).
Reset Button
By the use of a pencil the reset button can be pushed (R). This will clear all programmes apart from those factory pre set.
Reset is only possible with switch (A) in set Clock position!
x
BECAUSE OF OUR CONSTANT ENDEAVOUR FOR IMPROVEMENT DETAILS
MAY VARY SLIGHTLY FROM THOSE QUOTED IN THESE INSTRUCTIONS.
Should you require help with any difficulties
call our Technical Service Helpline on
08707 282 885
PO BOX 3774, Sutton Coldfield, West Midlands B76 8DH
Tel: 08707 282 885 Fax: 08707 282 886
ALL SPECIFICATIONS SUBJECT TO CHANGE
Please note - to avoid incurring unnecessary expense, in the event of a boiler shut down, check this in not caused by
lack of electricity supply, gas supply or low water pressure before calling our Customer Service Helpline.