Ferroli MAXIMA 35 S Troubleshooting guide

Appr. nr. B02.01 - CE 0063 B0 3924
MAXIMA 35 S
WALL-MOUNTING GAS BOILER,
PRE-MIXED
CONDENSING SYSTEM BOILER
INSTRUCTIONS FOR USE,
INSTALLATION
AND MAINTENANCE
code 3544786/0 ed. 01/2004
G C N° 47-267-21
Seasonal Efficiency
(SEDBUK)
band A (91,0%)

Maxima 35 S
2
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”.
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 instal-
lation, 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, isolate
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 partsonly. Failure toadhere to theabove
may compromise the safety of the appliance.
• To guarantee efficient operation, the appliance must
be serviced once a year by a Corgi registered engi-
neer.
• 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 thou-
rougly.
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)
President and Legal Representative
Cav. del Lavoro
Dante Ferroli

Maxima 35 S
3
1. OPERATING INSTRUCTIONS..................................................................4
1.1 Introduction ............................................................................................................4
1.2 Control panel ..........................................................................................................5
1.3 Turning ON and OFF ..............................................................................................7
1.4 Adjustments ............................................................................................................7
1.5 Maintenance............................................................................................................7
1.6 Faults.......................................................................................................................7
2. INSTALLATION .......................................................................................8
2.1 General Instructions................................................................................................8
2.2 Boiler location .........................................................................................................9
2.3 Boiler water connections ......................................................................................10
2.4 Connection to the gas system..............................................................................12
2.5 Electrical Connections ..........................................................................................12
2.6 Flue system ...........................................................................................................15
2.7 Condensate outlet connection .............................................................................21
3. SERVICE AND MAINTENANCE............................................................23
3.1 Adjustments ..........................................................................................................23
3.2 Initial start-up........................................................................................................24
3.3 Maintenance..........................................................................................................25
3.4 Troubleshooting....................................................................................................27
4 TECHNICAL CHARACTERISTICS AND DATA.........................................29
4.1 Dimensions and connections ................................................................................29
4.2 General view and main components ....................................................................30
4.3 Hydraulic diagram.................................................................................................31
4.4 Technical data table..............................................................................................32
4.5 Diagrams ...............................................................................................................33
4.6 Wiring diagram .....................................................................................................34

4
Maxima 35 S
1. OPERATING INSTRUCTIONS
1.1 Introduction
Dear Customer,
Thank you for choosing Maxima 35 S, a FERROLI wall-mounted boiler of the latest generation, featuring
advanced design and cutting-edge technology.
Maxima 35 S is a high-efficiency condensing pre-mix appliance for heating with extremely low emissions,
running on natural gas or LPG.
The boiler consists of an aluminium laminar heat exchanger providing effective condensation of the
water vapour contained in the flue gases, permitting extremely high efficiency.
Above the heat exchanger, in the boiler, there is a pre-mix burner, with a large ceramic surface, equip-
ped with electronic ignition and ionization flame control, which achieves extremely low emissions while
ensuring high reliability and long life operation.
The boiler is totally room sealed from the installation room: the air needed for combustion is drawn
from outside. The boiler also includes a modulating speed fan, modulating gas valve, pump, expansion
vessel, safety valve, temperature sensors, a safety thermostat and a low pressure sensor.
Thanks to the twin microprocessor control and adjustment system with advanced self-diagnosis, unit
operation is for the most part automatic. The power for heating is automatically governed by the control
system.
The user only has to set the temperature desired inside the home by means of a room thermostat and
appliance temperature control. The adjustment and control system will provide optimum operation
throughout the year.
The display continuously provides information on the unit’s operating status and it is easily possible
to obtain additional information on the sensor temperatures, set-points, etc. or configure them. Any
operating problems associated with the boiler or system is immediately signalled by the display and, if
possible, corrected automatically.

Maxima 35 S
5
1.2 Control panel
ON
OFF
4
6
15 13 16 1118
34
30
35
5
17
21
22
23
24
10
9
8
fig. 1
4 - Heating temperature adjustment control
To increase the heating temperature, turn the knob clockwise; anticlockwise to decrease it.
The adjustment range goes from 20 to 90°C (see page 7).
5 - RESET key
The Reset key is used to reset boiler operation when it has shut down.
To reset the boiler, press Reset (5 - fig. 1).
The shutdown condition is indicated by a fault code flashing and RESET being displayed.
6 - Power key
Turning the boiler on and off (on - green light on button pushed in).
8 - Mode key
Multifunction key.
9 - MINUS key
The MINUS key is used, toghether with PLUS key, to enter/exit the INSTALLER TEST mode (15mins).
10 - PLUS key
The PLUS key is used, toghether with MINUS key, to enter/exit the INSTALLER TEST mode (15mins).
11 - Return heating temperature display
In stand-by mode, the display shows the temperature of the return heating leaving the boiler.

6
Maxima 35 S
13 - Fan symbol
This appears when there is a call for heating, and the fan is operating.
15 - Ignition symbol
The ignition symbol appears during the ignition phase.
16 - Flame symbol
Indicates the burner is on, the small rising bars to the right indicate the burner output 1=low, 5=high.
17 - Radiator symbol
Displayed during demand or when the appliance is in standby.
18 - Flow heating temperature display
During operation, the display shows the temperature of the heating water leaving the boiler. When
operating knob “4” the display briefly shows the adjustment temperature being set ( see page 7 section
1.4 adjustments).
21 - Heating pump symbol
Displayed when the heating pump is operating.
22 - Appliance Frost protection
This appears when the boiler automatically comes on in frost protection, that is when the appliance
temperature drops under 5°C.
The appliance shuts down when it reaches a flow temperature of 15°C.
23 - Symbol showing demand for heating
Displayed when the appliance has a demand from external controls.
24 - Delay time symbol
Displayed when the appliance is in Stand-by after the set point operating temperature is achieved.
30 - System pressure display
Displays the heating system pressure (see page 11).
34 - TEST symbol
Boiler operating in TEST mode (full power). To turn on TEST mode, hold down the “+” and “-” keys for
3 seconds. Press the “+” and “-” keys for another 3 seconds to exit. TEST operation turns off automa-
tically after 15 minutes (Boiler operates at 100% whilst in test mode).
35 - Fault and parameter display
Displays any fault code if they should occur (see page 27 troubleshooting).

Maxima 35 S
7
1.3 Turning ON and OFF
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.
• Press the ON/OFF key in to turn on boiler (see fig. 1 Item 6).
• The boiler is now ready to function automatically whenever the externals controls are calling.
Turning off
Press the ON/OFF key (see fig. 1 Item 6).
When the boiler is turned off with this button, the P.C.B. is no longer powered and the frost
protection will be disabled.
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 a room thermostat)
Using the room thermostat, set the temperature desired in the room. Controlled by the room thermo-
stat, the boiler lights and heats the system water to the system setpoint temperature. The burner shuts
down when the desired temperature in the room is reached.
A room thermostat & programmer is a mandatory requirment (building regs Doc “L” 2002).
C.H. temperature adjustment
To set the system flow temperature, use the C.H. control knob. Turning it
clockwise increases the temperature, turning it anticlockwise decreases it.
When adjusting the control knob the display will flash for 5 seconds and
display the set point temperature. It will then revert to showing actual
temperature.
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
In the unlikely event of an operating problem or component failure, the display flashes and a fault iden-
tification code appears.
Faults marked with the letter “F” cause temporary shutdowns that are automatically reset as soon as
the value comes back within the boiler’s normal working range.
If together with the fault the display also shows RESET, the user must reset boiler operation by pressing
the key (5 - fig. 1). The ignition cycle will thus be repeated.
If the problem remains after two attempts at resetting, contact the Ferroli Service Centre.
For other faults, refer to page 27 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.

Maxima 35 S
8
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

Maxima 35 S
9
Minimum
A
B
D
2,5 cm
20 cm
60 cm
(via an openable panel)
C40 cm
Table 1
fig. 2
A A
B
D
C
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.

Maxima 35 S
10
fig. 3
1 3 5
240240
43
240 240
60
200
138 138 53
7
288
8
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 plum-
bing 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 etc.
If the flow 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 type “A” drain cocks at the lowest points in the system
to allow 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, calobrated 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 operation (BS 7593 Building regs Doc L).
Make the connections to the appliance as shown in fig. 3.
Key
1 System flow (22 mm with isolation valve fitted)
3 Gas inlet (22 mm with isolation valve fitted)
5 System return - 22 mm with isolation valve fitted (c/w filter)
7 Condense outlet
8 Safety valve discharge 1/2” f/I
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 diameter copper pipe (with a continual
fall from the boiler) 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 bri-
ckwork 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).

Maxima 35 S
11
Fig. 5
3
2
1
4
Key
A = Nut
B = Compression olive
D = 3/4 seal (green)
F = 1/2 gas seal (blue)
G=Filter
H = Cap
Flow isolation valve
Gas isolation valve
Return isolation valve
22
22
22
A
A
AB
B
B
D
D
F
GH
RED
YELLOW
BLUE
fig. 4
The Isolation valve kits shown in fig. 4 are supplied as standard.
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. Ensure the filling point is on the return pipe to the boiler.
Fittings manufactured from duplex (alpha-beta) brass are not acceptable for underground use and certain
water undertakings will not accept their use above ground.
Key
1. C.H. filling valve.
2. Temporary connection.
3. Cold water supply valve.
4. Double check valve.

Maxima 35 S
12
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. Sentinel Division
Tandern house, Marlowe Way Betz Dearborn LTD
Croydon, surrey, CRO 4YS Widnes, Cheshire WA8 8ND
Tel: [phone] 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.
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 sup-
plier.
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 pres-
sures 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 26 (combuston analyser testing).
The Isolation valve kits shown in fig. 4 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 cross sectional area 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 which

Maxima 35 S
13
Wiring diagram
Fig. 6a
MAXIMA
FERROLI
BOILER
D.H.W.
Zone Valve
Auto
air
vent
C.H.
Zone Valve
Automatic
bypass
(mimimum flow of 6l/min.)
Heating return
Heating flow
Fig. 6b
4321
Junction Box
NEL
Terminal 4 - SWITCH LINE
230V A/C
12345678910
PROGRAMMER
DHW ON
CH ON
NEUTRAL
LIVE
CH
zone
valve
DHW
zone
valve
Room Thermostat
Cylinder Thermostat
N
E
L
230 Vac
fused at
3 amps
BROWN BLUE
GREY ORANGE
L
5
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.
Standard Systems
For a general pipe layout and wiring diagram on the “S” and “Y” plan systems please see fig.
6a, 6b, and 7a, 7b.
MAXIMA “S” Plan
Pipe layout

Maxima 35 S
14
MAXIMA “Y” Plan
Pipe layout
MAXIMA
FERROLI
BOILER
Auto air vent
Automatic
bypass
(mimimum flow of 6l/min.)
Heating return
Heating flow
Wiring diagram
4321
Junction Box
NL
12345678910
PROGRAMMER
NEUTRAL
LIVE
CH ON
DHW ON
DHW OFF
BLUE
WHITE
GREY
ORANGE
Room Thermostat
Cylinder Thermostat
N
E
L
240 Vac
fused at 3 amps
Honeywell V4073H mid position
The heating system must have an automatic
bypass capable of
passing 6 litres/minute
3 WAY ZONE VALVE
2
1
C
Terminal 4 - SWITCH LINE
230V A/C
L
5
fig. 7a
fig. 7b

Maxima 35 S
15
1
2
3
2
4
A
fig. 8
Terminal board wiring diagram
System External controls
Switch Line
230V
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.
Access to the electrical terminal board
Follow the diagram shown below to access the electrical connection terminal board
(A fig. 8). The layout of the terminals for the various connections is given in section 4.6 wiring diagram
fig 23.
Room thermostat
CAUTION: the externals controls must supply 230V - 50Hz to terminal n° 4 (fig. 8).
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 indi-
cated, 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 noted that only Ferroli flue system and accessories must be used on this appliance,
as per BS 5440 2000 and C.E. test certification.

Maxima 35 S
16
* = between
10 and 60 mm
* = between
10 and 60 mm
240 240
Install level
50*115
95
80
30 50*
30
95
80
80
S 50*
P
115
L
DS
P
125
S
30
95
DS50*
L
30
95
240 240
180
240240
180
Drill the wall 10÷20 mm
more than the pipe diameter
Install level
Install level
Install level
Drill the wall 10÷20 mm
more than the pipe diameter
Standard 1KWMA53A
Flue kit Side view
View from above
fig. 10a
Side Outlet
fig. 10b
Front view
View from above
P = S + 165 mm
Rear Outlet
L = S + D + 175 mm
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.
Standard concentric flue installation
Horizontal flue installation
1. Define the position for installing the unit.
2. If using standard flue (1KWMA53A) this must be installed level, for non-standard flue lenghts
over 1mtr 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.

Maxima 35 S
17
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.
Vertical flueing
The installation of a concentric vertical flue can be carried out as follows,
Install the appliance as previously mentioned in this manual.
1. Connect onto the flue assembly at the top of the appliance a concentric vertical adaptor part number
1KWMA71W.
2. Use the required amount of 1mtr flue extensions (part number 1KWMA56U) inserting them spigot
down ensuring the seals are well lubricated with silicone grease (not supplied) and correctly located
into the sockets.
3. If required 45° bends (Part number1KWMA64A) may be used with a resistance value of 0.5mtrs each,
the flue should be routed in such away to avoid any
unnecessary deviation and thus minimise the amount
of bends required.
4. The termination should be madethrough our concentric
flue outlet (part number 1KWMA83U) in conjunction
with a roof slate pitched (part number 1KWMA82U)or
flat roof (part number 1KWMA81U) The storm collar
must be fixed on using the three screws provided and
sealed with an external grade silicone (not supplied).
5. For longer flue lengths a 125mm concentric flue system
is available.
6. All flue installations must comply with BS5440 part 1
and must only be of Fèrroli manufacture. The vertical
flue must continually rise and be supported throughout
its length. The flue must be inspected whilst commis-
sioning the appliance to ensure it is sound throughout
its length.
This information is for guidance purposes and Fèrroli will
in no way be held responsible for incorrect installation
following this guide.
Vertical Outlet
fig. 10c
Angled roof tile
1KWMA82U
1KWMA56U
240 240
950
50
1KWMA71W
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
5 m 12 m
Ø mm
80/125
Table 2a
Maximum permissible
duct length (vertical) 6 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 sup-
plied)

Maxima 35 S
18
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
2
Ø80
AIR
Ø80
FUMES
Remove
the closing
cap
1
180
367
120 120 120120
80 84 80
Two pipe adaption
kit cod. 1KWMR54A
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 per-
missible 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.

Maxima 35 S
19
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
fig. 13

Maxima 35 S
20
Minimum Dimensions of Flue Terminal Positions
Directly below an opening, air brick,
opening windows, etc.
Above an opening, air brick,
opening windows, etc.
Horizontally to an opening, air brick,
opening windows, etc.
Below gutters, soil pipes or drain pipes
Below balconies or car port roof
Below eaves
From a vertical drain pipe or soil pipe
From an internal or external corner
From a surface facing the terminal
From a terminal facing the terminal
From the wall on which the terminal is mounted
From a vertical structure on the roof
Above intersection with roof
Horizontally from a terminal on the same wall
Vertically from a terminal on the same wall
From an opening in the car port (e.g. door,
window) into the dwelling
Above ground roof or balcony level
300mm
300mm
300mm
200mm
75mm
200mm
150mm
100mm
300mm
600mm
300mm
300mm
150mm
1200mm
1200mm
1500mm
N/A
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
NOTE
N/A = Not applicable
In addition, the terminal should not be nearer than 150mm (fanned draugt) or
300mm (natural draugt) to an opening in the building fabric formed for the purpose
of accommodating a built-in element such as a window frame. Separation distances
are linked to the rated heat inputs as shown.
Condensing Terminal Positions: If the flue is to be terminated at low level, then the
potential effect of the plume must be considered.
The plume should not be directed: across a frequently used access route
across a neighbouring property
towards a window or door