Ferroli DOMIcompact F 24 B Parts list manual

wall-mounted gas fired,
condensing combination boiler
FERROLI F 24 B
cod. 3540B29/1 - 04/2005
Seasonal Efficiency
(SEDBUK)
band B
INSTRUCTIONS FOR USE, INSTALLATION AND MAINTENANCE

2
Ferroli F 24 B
IMPORTANT
Your "benchmark" Installation, Commissioning and Service Record Log Book is enclosed in the
last pages of this manual. “This record must be completed and left with the end user”.
Ferroli 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.
• Read the warnings given in this manual thoroughly.
They provide important information for safe
installation, use and maintenance
• The instruction manual, by law must be left with
the end user.
• If the appliance is sold or transferred to another
owner or if the owner moves, leaving the appliance
behind, always ensure that the manual is kept
with the appliance for consultation by the new
owner and /or installer.
• Incorrect installation or poor maintenance absolves
the manufacturer from all liability for damage to
persons and property.
• Installation and maintenance must be carried out
in accordance with current legislation, according
to the manufacturer’s instructions and by qualified
corgi registered engineer.
• Before service or maintenance work is carried out
isolate the appliance from the mains electricity
supply.
• In the event of malfunction or faulty operation, iso-
late the appliance. Do not attempt to repair or carry
out any other operation on the appliance directly.
Contact Ferroli or a qualified engineer only.
• Repairs or the replacement of components must
be carried out exclusively by qualified personnel
using original spare parts only. Failure to adhere
to the above may compromise the safety of the
appliance.
• To guarantee efficient operation, the appliance
must be serviced once a year by a Corgi registered
engineer.
• The appliance may not be used for purposes other
than those for which it was explicitly designed.
• Incorrect installation and use or failure to follow the
instructions provided by the manufacturer absolve
the manufacturer from all liability for damage.
• After unpacking, check that the contents are correct
and undamaged.
• Keep packing out of reach of children as it could be
potentially hazardous.
• To clean external parts, use a damp cloth moistened
with soapy water if necessary. Avoid using abrasive
cleaning products and solvents.
This symbol indicates “Caution” and is placed next to all safety information.
Strictly follow these instructions in order to avoid danger and damage to
persons or property.
This symbols calls attention to a note or important information, please read
thourougly.
President and Legal Representative
Cav. del Lavoro
Dante Ferroli
•
•
•
•
Declaration of conformity
Manufacturer: FERROLI S.p.A.
Address: Via Ritonda 78/a 37047 San Bonifacio VR Italy
declares that this unit complies with the following EU directives:
Gas Appliance Directive 90/396
Efficiency Directive 92/42
Low Voltage Directive 73/23 (amended by 93/68)
Electromagnetic Compatibility Directive 89/336 (amended by 93/68)

3
Ferroli F 24 B
1. OPERATING INSTRUCTIONS..................................................................4
1.1 Introduction ............................................................................................................4
1.2 Control panel ..........................................................................................................5
1.3 Operating instructions............................................................................................6
1.4 Adjustments ............................................................................................................6
1.5 Maintenance............................................................................................................7
1.6 Faults.......................................................................................................................7
1.7 Time Clock ..............................................................................................................8
2. INSTALLATION .......................................................................................9
2.1 General Instructions................................................................................................9
2.2 Boiler location .......................................................................................................10
2.3 Boiler water connections ......................................................................................12
2.4 Connection to the gas system..............................................................................14
2.5 Electrical Connections ..........................................................................................14
2.6 Flue system ...........................................................................................................15
2.7 Condensate outlet connection .............................................................................22
3. SERVICE AND MAINTENANCE............................................................24
3.1 Adjustments ..........................................................................................................24
3.2 Initial start-up........................................................................................................26
3.3 Maintenance..........................................................................................................27
3.4 Troubleshooting....................................................................................................29
4 TECHNICAL CHARACTERISTICS AND DATA.........................................33
4.1 Dimensions and connections ................................................................................33
4.2 General view and main components ....................................................................34
4.3 Hydraulic diagram.................................................................................................35
4.4 Technical data table..............................................................................................36
4.5 Diagrams ...............................................................................................................37
4.6 Wiring diagram .....................................................................................................38
Benchmark................................................................................................40

4
Ferroli F 24 B
1. OPERATING INSTRUCTIONS
1.1 Introduction
Dear Customer,
Thank you for choosing FERROLI F 24 B, a FERROLI wall-mounting boiler featuring advanced design
and technology, high reliability and quality construction. Please read this manual carefully and keep it
for future reference.
FERROLI F 24 B is a high-efficiency condensing appliance for heating and hot water production run-
ning on natural or liquefied petroleum gas (configurable at the time of installation) and regulated by an
advanced microprocessor control system.
The boiler shell consists of a primary copper laminar heat exchanger, a secondary aluminium heat
exchanger providing effective condensation of the water vapour contained in the flue gases, and burner
equipped with electronic ignition and ionization flame control.
The boiler is totally room sealed from the installation room: the air needed for combustion is drawn
from outside. The boiler also includes a fan, modulating gas valve, pump, expansion vessel, flow meter,
safety valve, flow sensor, temperature sensors, a safety thermostat and a low pressure sensor.
Thanks to the microprocessor control and adjustment system with advanced self-diagnosis, unit ope-
ration is for the most part automatic. The power for heating is automatically governed by the control
system according to the indoor characteristics of the building and its location. The power for hot water
is automatically and continually governed to ensure a fast delivery and comfort under all operating
conditions.
The user only has to set the temperature desired inside the home (by means of an optional room
thermostat, which is required under the building regulations 2002) or regulate the temperature of the
system, and set the desired outlet temperature for the hot water. The adjustment and control system
will provide optimum operation throughout the year.

5
Ferroli F 24 B
Fig. 1
1.2 Control panel
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.
KEY DESCRIPTION
ASwitch OFF/ON/RESET
BCentral heating flow
temperature regulation
CD.H.W. temperature
regulation
DWater pressure gauge
ETime clock
bar
RESET
OFF
ON
0
5
1
234
6
bar
ABC D
°C°C
E
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)
12345
1
2
3
4
5
LED

6
Ferroli F 24 B
1.3 Operating instructions
Ignition
• Open the gas isolation valve upstream of the boiler.
• Purge the air from the pipe upstream of the gas valve.
• Ensure power is on to appliance.
• Turn the switch A(fig. 1) to the ON position.
• The boiler is now ready to function automatically whenever hot water is drawn or the clock and room
thermostat calls for heating.
Turning off
Turn the switch A(fig. 1) to the OFF position.
When the boiler is turned off with this button, the P.C.B. is no longer powered and the frost
protection will be disable.
Close the gas cock upstream of the boiler and disconnect the electrical power supply.
To avoid damage caused by freezing during long shutdowns in winter, it is advisable to drain
all water from the boiler, the tap water and the system water.
1.4 Adjustments
Room temperature adjustment (with optional room thermostat)
Using the room thermostat, set the temperature desired in the room. Controlled by the room thermostat,
the boiler lights and heats the system water to the set system setpoint temperature. The burner shuts
down when the desired temperature in the rooms is reached.
A room thermostat is a mandatory requirment (building regulations Doc “L” 2002).
C.H. temperature adjustment
To set the system flow temperature, use the C.H. control knob B(fig. 1).
Turning it clockwise increases the temperature, turning it anticlockwise
decreases it.
Domestic hot water temperature adjustment
To set the hot water temperature, use the D.H.W. control knob C(fig. 1).
Turning it clockwise increases the temperature, turning it anticlockwise
decreases it.
Hot Water Only - “SUMMER” ( )
To obtain hot water only from the boiler, turn switch (Afig. 1) to the on position. The top green light
on the left side of the control panel is illuminated (power on ).
Turn the temperature regulator (Bfig. 1) 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 (Cfig. 1) clockwise
to increase and anti-clockwise to decrease the water temperature.
°C
60
80
50 70
40
°C

7
Ferroli F 24 B
Heating and Hot Water - "WINTER” ( )
To obtain heating from the boiler, turn the temperature regulator (Bfig. 1) clockwise to the maximum
position, ensure that any other heating controls e.g. room thermostats, clock etc. are in the on posi-
tion.
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.
Frost Protection
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.
1.5 Maintenance
It is strongly recommended to carry out annual maintenance on the boiler and the heating system. Please
refer to the “maintenance” section in this manual.
The casing, the control panel and the aesthetic parts of the boiler can be cleaned using a soft and damp
cloth.
Do not use abrasives or solvents.
1.6 Faults
Low water pressure
Low pressure will be indicated by flashing light in the middle of the facia illuminating (
bar
).
The boiler pressure gauge (Dfig. 1) should read at least 1 bar.
Boiler lock out
In the event of the red lockout light ( ) coming on, the on/off/reset switch (Afig. 1) 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). Check gas supply or condensate discarge. Clean condensate
discharge if dyirty or obstructed. If the lockout light ( ) illuminates repeatedly, contact an approved
Férroli service engineer.
If the problem remains after two attempts at resetting, contact the Ferroli Service Centre.
For other faults, refer to section 3.4 “Troubleshooting.”
Before calling the Ferroli service centre, check that the problem is not due to an installation
error or a problem with the gas/electricity or low water pressure in the system.

8
Ferroli F 24 B
1.7 Time Clock
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
A
B
E
RDP
AUTO P
OI
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
To Set Own ON and OFF times. Symbol in Display = ON time
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 it is OFF; and OFF if it is ON
F I=Heating continuous - AUTO=Heating timed - O=Heating disabled
R Reset (with pencil) only with switch Ain set clock position
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.
6:30 1
8:30 2
12:00 3
12:00 4
6:00 1
9:00 2
12:30 3
14:00 4
16:30 5
22:30 6
16:00 5
23:30 6
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!

9
Ferroli F 24 B
2. INSTALLATION
2.1 General Instructions
This device must only be used for the purpose for which it is specially designed. This unit is
designed to heat water to a temperature below boiling point and must be connected to a hea-
ting system and/or a water supply system for domestic use, compatible with its performance,
characteristics and its heating capacity. Any other use is considered improper.
BOILER INSTALLATION MUST ONLY BE PERFORMED BY QUALIFIED PERSONNEL, IN ACCORDANCE
WITH ALL THE INSTRUCTIONS GIVEN IN THIS TECHNICAL MANUAL, THE PROVISIONS OF CURRENT
LAW, THE RECOMENDATION OF BS STANDARDS, ANY LOCAL REGULATIONS AND THE RULES
OF COMPEDENT WORKMANSHIP.
Incorrect installation can cause damage or physical injury for which the manufacturer declines
any responsibility.
This appliance must be installed strictly in accordance with these instructions
and regulations:
The Gas Safety Regulations (Installations & Use).
The Local Building Regulations.
The Building Regulations (Part L).
The Buildings Standards (Scotland - Consolidated) Regulations.
British Standards Codes of Practice:
B.S. 5440 Part 1 Flues
B.S. 5440 Part 2 Air supply
B.S. 5449 FORCED CIRCULATION HOT WATER SYSTEMS
B.S. 6798 INSTALLATION OF GAS FIRED HOT WATER BOILERS
B.S. 6891 GAS INSTALLATIONS
B.S. 7671 IEE WIRING REGULATIONS
B.S. 4814 SPECIFICATION FOR EXPANSION VESSELS
B.S. 5482 INSTALLATION OF LPG
B.S. 7593 TREATMENT OF WATER IN DOMESTIC HOT WATER CENTRAL HEATING SYSTEMS
B.S. 5546 INSTALLATION OF HOT WATER SUPPLIES FOR DOMESTIC PURPOSES
Model Water Bye Laws
B.S. 5955-8 PLASTIC PIPEWORK INSTALLATION
For Northern Ireland the rules in force apply

10
Ferroli F 24 B
Minimum
A
B
D
5 cm
20 cm
60 cm
(via an openable panel)
C20 cm
Table 1
fig. 2
2.2 Boiler location
The unit’s combustion circuit is sealed off from the installation room. The installation room must be
sufficiently well ventilated to prevent any dangerous conditions from forming in the event of even slight
gas leakage. This safety standard is required by the EEC Directive no. 90/396 for all gas units, including
those with a so-called sealed chamber.
Therefore the place of installation must be free of dust, flammable materials or objects or corrosive
gases. The room must be dry and not subject to freezing.
The boiler is design to be installed on a solid wall. The wall fixing must ensure a stable and effective
support for the appliance, using the bracket and fixings supplied.
If the unit is enclosed in cupboard or mounted alongside, there must be space for normal maintenance
work. Fig. 2 and tab. 1 give the minimum clearances to leave around the unit.
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 70mm deep to accept the wall plugs. Fit standard wall plugs on the left and
right side and the special wall plug in the middle (fig. 3). Fix the wall bracket to the wall using standard
lock nut (M8) on both sides. Mount the boiler on the wall bracket and fix using the special antitheft nut
(M8) as described in the fig. 3. Using a core drill cut a 118mm diameter hole for the flue.
Fig. 3
A A
B
D
C

11
Ferroli F 24 B
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. The supplied temporary filling loop is shown in fig. 5. Ensure
the filling point is on the return pipe to the boiler.
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: An automatic bypass must
be fitted as far as possible from the
boiler if thermostatic radiator valves
are fitted thoughout.
Fig. 4
Gas
Hot water
Additional expansion
vessel C.H. (if required)
Filling
point C.H.
Automatic
Bypass
Key
1. Filling point C.H.
2. Temporary connection
3. Cold water supply
4. Double check valve
Fig. 5
3
2
1
4

12
Ferroli F 24 B
2.3 Boiler water connections
The heating capacity of the unit should be previously established by calculating the building’s heat
requirement according to current regulations. For good operation and long life of the boiler, the plumbing
system must be well proportioned and always complete with all those accessories that guarantee regular
operation and running, room thermostat, trv’s and automatic bypass.
If the delivery and return pipes follow a path where air pockets could form in certain places, it is esential
to install vent valves at these points. Also, install a type “A” drain cock device at the lowest point in
the system to allow its complete draining.
The temperature differential between the flow manifold and the return to the boiler should
not exceed 20° C.
A minimum flow of 6 litres/min is requied through the heat exchanger, it is therefore essential to fit a
automatic bypass a min of 3 meters away from the appliance, calibrated on site.
Do not use the water system pipes to earth
electrical appliances.
Before installation, carefully flush all the pipes of the
heating system to remove residues or impurities that
could affect the unit’s good working (BS 7593 Building
regs Doc L).
Make the connections to the appliance as shown in
fig. 6.
Key
1 System flow (22 mm with isolation valve fitted)
2 DHW outlet (15 mm with isolation valve fitted)
3 Gas inlet (22 mm with isolation valve fitted)
4 Cold main inlet (15 mm with isolation valve fitted)
5 System return - 22 mm with isolation valve fitted (c/w
filter)
6 System drain
7 Condense outlet
It is essential to install the isolation valves supplied between the boiler and heating system, allowing
the boiler to be isolated from the system if necessary.
The safety valve outlet must be connected to a 15 mm pipe to allow system water out onto the
ground in the event of over-pressure in the heating circuit. If this is not done, and the drain valve
trips and floods the room, the boiler manufacturer is not to be held responsible. The outlet should
face back against the outer brickwork or building face to prevent harm or injury from hot water
discharging in the evet of an over-pressuried system.
Make the boiler connection in such a way that its internal pipes are free of stress. If a check valve is
installed on the tap water circuit (where applicable), it is necessary to mount a safety valve between
the boiler and this circuit (check valve minimum 3 meters from boiler).
fig. 6
1 2 3 54
9536 60 60 95 114
28
98
63
6
7

13
Ferroli F 24 B
The connecting kits shown in fig. 7 are supplied as standard.
Key
A=Nut
B = Compression olive
D=3/4” seal (green)
E = 1/2” seal (green)
F = 1/2” gas seal (blue)
G = Filter
H=Cap
Flow isolation valve
Hot water connection
Gas isolation valve
Cold water isolation valve
Return isolation valve
Ø22
Ø22
Ø22
Ø15
Ø15
A
A
A
A
AB
B
B
B
B
D
D
E
E
F
GH
fig. 7
Water treatment
When treatment is used ferroli limited only recommend the use of proprietary Brand, such as Fernox
or Sentinel water treatment products, which must be used in accordance with the manufactures
instructions. for further information contact:
Feronx Manufacturing Co. LTD.
Tandern house, Marlowe Way
Croydon, surrey, CRO 4YS
Tel: [phone]
Sentinel Division
Betz Dearborn LTD
Widnes, Cheshire WA8 8ND
Tel: [phone]
Note - When the boiler is installed with an existing or new system any unsuitable additives or system debris
must be removed by thorough cleansing. All systems should be cleansed according to B.S. 7593.
Note - In hard water areas treatment to prevent lime scale may be necessary.
Note - It is important that the correct concentration of the water treatment product is maintained in
accordance with the manufacturers instructions.

14
Ferroli F 24 B
2.4 Connection to the gas system
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 whitout 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.
Appliance inlet working pressure must be 20 mbar MINIMUM, for NG and 37 mbar minimum for pro-
pane.
Do not use pipes of a smaller size than the combination boiler inlet gas isolation valve (22 mm).
The complete installation must be tested for gas soundness and purged as described in BS6891. All
pipework must be adquately supported. An isolating gas valve is provided and should be fitted
on the boiler gas inlet. Please wait 10 minutes when ligthing from cold before checking the gas
rate. Gas pressures should be checked after the boiler has operated for 10 minutes to ensure
thermal equilibrium.
The appliance has no facility to check burner pressures, a combuston test should be carried out instead,
see page 29 (combuston analyser testing).
The connecting kits shown in fig. 7 are supplied as standard.
2.5 Electrical Connections
The unit must be installed in conformity with current national and local regulations.
Connection to the electrical grid
The boiler must be connected to a single-phase, 230 Volt-50 Hz electric line.
The unit’s electrical safety is only guaranteed when correctly connected to an efficient earthing
system executed according to current safety standards. Have the efficiency and suitability of
the earthing system checked by professionally qualified personnel. The manufacturer is not
responsible for any damage caused by failure to earth the system. Also make sure that the
electrical system is adequate for the maximum power absorbed by the unit, as specified on
the boiler dataplate, in particular ensuring that the section of the system’s cables is suitable
for the power absorbed by the unit.
The boiler is prewired and provided with a cable for connection to the electricity line. The connections
to the supply must be made with a permanent connection and equipped with a double pole switch
whose contacts have a minimum opening of at least 3 mm, and fused at max. 3A between the boiler
and the line. It is important to respect the polarities (LIVE: brown wire / NEUTRAL: blue wire / EARTH:
yellow-green wire) in making connections to the electrical supply.
The user must never change the unit’s power cable. If the cable gets damaged, switch off the
unit and have it changed solely by professionally qualified personnel. If changing the electric
power cable, use solely “HAR H05 VV-F” 3x0.75 mm2cable with a maximum outside diameter
of 8 mm.

15
Ferroli F 24 B
Room thermostat
CAUTION: THE ROOM THERMOSTAT MUST HAVE VOLTAGE FREE CONTACTS. CONNECTING
230 V. TO THE TERMINALS OF THE TIME CLOCK AND ROOM THERMOSTAT WILL IRREPARABLY
DAMAGE THE P.C.B.
When connecting a room thermostat with a daily or weekly program, or a timer switch, do not
take the power supply for these devices from their cut-out contacts. Their power supply must
be taken with a direct connection to the mains or with batteries, depending on the type of
device (isolation to mains fed clocks via a 3amp fused spur).
Access to the electrical terminal board
Follow the instructions Agiven in fig. 8a to access the electrical connection terminal board
(Bfig. 8b). The layout of the terminals for the various connections is given in the wiring diagram in the
Technical Data chapter.
B
fig. 8a fig. 8b
A
2.6 Flue system
The unit is “type C” with a sealed chamber and forced draught, the air inlet and flue outlet
must be connected to one of the following flue systems. With the aid of the tables and methods
of calculation indicated, before commencing installation, it is first necessary to check that the
flue system does not exceed the maximum permissible length. The current standards and local
regulations must be observed.
It should be notes that only Ferroli flue system and accessories should be used on this appliance,
as per BS 5440 2000 and C.E. test certification.

16
Ferroli F 24 B
1
Restrictor
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. 9).
Fig. 9
Choice of 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
RESTRICTOR FOR TWO PIPE SYSTEM
Total flow resistance
of flue system
Use
restrictor
size
minimum maximum mm
0 m 20 m 43
20 m 55 m No restrictor
RESTRICTOR FOR CONCENTRIC SYSTEM
Flue lenght up to:
Use
restrictor
size
Concentric
60 / 100
1 bend + 1 meter 43 mm
1 bend + 3 meters No restrictor
Concentric
80 / 125
1 bend + 5 meters 43 mm
1 bend + 12 meters No restrictor
N.B.: the diameter of the hole is
stamped on the restrictor
• With concentric systems:
- Choose correct restrictor from table
below.

17
Ferroli F 24 B
Connection with concentric flue system
The unit can be connected to a concentric air/flue duct with a wall or rooftop outlet as shown on the
following drawings. Numerous accessories are available on request to meet the various installation
requirements. Please refer to our “flue manual” or the price list.
Horizontal concentric flue installation
Horizontal flue installation
1.Define the position for installing the unit.
2.If using (1KWMA56W) this must be installed level, for non-standard flue lenghts over im a fall of 3 mm
per metre should be incorporated.
3.Make a hole of diameter 10 - 20 mm greater than the nominal diameter of the concentric pipe used.
4.If necessary, cut the end pipe to size, ensuring that the external pipe protrudes from the wall by between
10 and 60 mm (Fig. 10a and 10b). Remove the cutting burrs.
* = between
10 and 60 mm
Drill the wall 10÷20 mm
more than the pipe diameter
010008X0
* = between
10 and 60 mm
Drill the wall 10÷20 mm
more than the pipe diameter
95
125S 50* 12550*
12550*SD
L
30
95
257203
L
P
50*S
100
100
95
30
257203
30
Install level
Install level
1KWMA56W
Install level
Install level
D S
95
30
P
203 257
Side view
View from above
fig. 10a
Side Outlet
fig. 10b
Front view
View from above
P = S + 85 mm
Rear Outlet
L = S + D + 242 mm

18
Ferroli F 24 B
Vertical Outlet
fig. 10c
The total length in equivalent metres of the
concentric flue must not exceed the maximum
lengths stated in the following table, note that
each bend gives rise to the stated reduction.
For example, a duct = 60/100 composed of 1
bend of 90° +1 horizontal metre + 2 bends of
45° + 1 horizontal metre has a total equivalent
length of 4 metres. Angled roof tile
1KWMA82U
1KWMA56U
950
50
010009X0
max. 6 metres 60/100 max. 12 metres 80/125
Roof end piece
1KWMA83U
68
95050
50 950
50
1000 125
10
Reduction factors for bends
Concentric bend at 90°- Ø 60/100 mm
Concentric bend at 45°- Ø 60/100 mm
Concentric bend at 90°- Ø 80/125 mm
Concentric bend at 45°- Ø 80/125 mm
1m
0.5 m
0.5 m
0.25 m
Table 2b
Maximum permissible
duct length (Horizontal)
Ø mm
60/100
3 m 12 m
Ø mm
80/125
Table 2a
Maximum permissible
duct length (vertical) 4 m 12 m
5.Connect the flue to the boiler, positioning the seals correctly. Seal the flue into the wall with silicone or
sand + cement and cover with wall seals provided.
Flue seals should be lubricated with a silicone type grease to prevent damage (grease
not supplied)

19
Ferroli F 24 B
1
3
4
2
1KWMA84U
Ref.
1
2
3
4
N°Pieces
16
16
1
1
Vertical flue pipe Ø80
Vertical air pipe Ø80
Vertical flue terminal
Two pipe adaption kit (1KWMR54A)
Description Equivalent
loss
25,6 m
16,0 m
12,0 m
0,0 m
53,6 m
Total
Table 3
fig. 11
fig. 12
Connection with 80 mm pipe system
The unit can be connected to a system of
separate air/flue pipes for a wall or rooftop
outlet as shown on the fig. 11 - 12. Numerous
accessories are available on request to meet
the various installation requirements.
Please refer to the flue manual catalogue or the
price list for additional components.
To check you do not exceed the maximum
permissible flue length, it is necessary to make
a simple calculation before installation:
1. For each component, tables 4 - 5 provide an
“equivalent loss in metres”, depending on
the position of installation of the component
(with air intake or flue extraction, vertical
or horizontal).
The loss is called “equivalent length” since it
is compared to the loss of one metre of flue
(defined as equal to 1). For example, a bend
at 90° of Ø80 in flue run has an equivalent loss
of 2.5 linear metres, i.e. it has a loss equal to
that of 2.5 metres of flue length.
2. After completely designing the layout of
the system, add up the losses in equivalent
metres, depending on the installation posi-
tion, of all the components and accessories
in the system.
3. Check that the total calculated loss is less
than or equal to 55 equivalent metres, i.e.
the maximum permissible for this model
of boiler.
For complete flue options please con-
tact FERROLI or check our comprensive
flue manual.
2
Ø80
AIR
Ø80
FUMES
Remove
the closing
cap
1
Two pipe adaption
kit cod. 1KWMR54A

20
Ferroli F 24 B
Table of flue and accessory
KWMA86A
KWMA85A
KWMA84U
Air Flue
Vertical Horizontal Vertical Horizontal
KWMA65W
KWMA01W
KWMA83W • 1,00 m
Description
Pipe Ø 80
male-female
Bend 45°Ø 80 mm
male - female
Bend 90°Ø 80 mm
male - female
Description
Horozontial
flue terminal
Horozontial
air terminal
Vertical flue
terminal
1 1 1.6 2
1.2 1.8
1.5 2.0
Equivalent losses in
metres (linear)
5
2
Air Flue
Vertical Horizontal Vertical Horizontal
Equivalent losses in
metres (linear)
12
Accessories Ø 80 Accessories Ø 80
Table 4 Table 5
The stated loss values refer to genuine Ferroli flue accessories.
Terminal Position
P
D, E
Q
Q
l
BC
A
G
F
L
J
HH
K
N
N
MM
Q