Potterton Performa 24 User guide

Installation and Servicing Instructions
Performa 24
Gas Fired Wall Mounted Combination Boiler
Please leave these instructions with the user

0011210500
Dear Customer,
We are sure your new boiler will comply with
all your requirements.
Purchasing one of the POTTERTON products
satisfies your expectations: good functioning,
simplicity and ease of use.
Do not dispose of this booklet without reading
it: you can find here some very useful
information, which will help you to run your
boiler correctly and efficiently.
Do not leave any parts of the packaging (plastic bags, polystyrene, etc.)
within children’s reach as they are a potential source of danger.
POTTERTON attests that these models of boiler bear the
CE mark in compliance with the basic requirements as laid
down in the following Directives:
- Gas Directive 90/396/CEE
- Performance Directive 92/42/CEE
- Electromagnetic Compatibility Directive 89/336/CEE
- Low Voltage Directive 73/23/CEE
POTTERTON
POTTERTON

3
0312_1718
Contents
Instructions pertaining to the user
Instructions prior to installation 4
Instructions prior to commissioning 4
Commissioning of the boiler 4
Room temperature adjustment 5
DHW temperature adjustment 5
Filling the boiler 6
Turning off the boiler 6
Prolonged standstill of the system. Frost protection
(central heating system) 6
Gas change 6
Safety Device Indicators-Activation 7
Servicing instructions 7
Instructions pertaining to the installer
General information 8
Instructions prior to installation 8
The template to fix the boiler on the wall 10
Boiler size 10
Installation of flue and air ducts 11
Connecting the mains supply 16
Fitting a room thermostat 16
Connecting a programming clock 16
Gas change 17
Control operation devices 20
Positioning of the ignition
and flame sensing electrode 22
Electronic board calibration 22
Check of combustion parameters 22
Output / pump head performances 23
How to purge the DHW system from
limestone deposits 23
How to disassemble the DHW heat exchanger 24
Cleaning the cold water filter 24
Boiler schematic 25
Illustrated wiring diagram 26
Technical data 27
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0209_2401
Instructions pertaining to the user
Instructions prior to installation
This boiler is designed to heat water at a lower than boiling temperature
at atmospheric pressure. The boiler must be connected to a central heating
system and to a domestic hot water supply system in compliance with
its performances and output power.
Have the boiler installed by a Qualified Service Engineer and ensure the
following operations are accomplished:
a) careful checking that the boiler is fit for operation with the type of
gas available. For more details see the notice on the packaging and
the label on the appliance itself.
b) that the terminal is not obstructed and that no other appliance exhaust
gases are expelled through the same flue duct, unless the flue is
especially designed to collect the exhaust gas coming from more than
one appliance, in conformity with the laws and regulations in force.
c) careful checking that, in case the flue has been connected to pre-
existing flue ducts, thorough cleaning has been carried out in that
residual combustion products may come off during operation of the
boiler and obstruct the flue duct thus engendering dangerous situations.
Instructions prior to
commissioning
Initial lighting of the boiler must be carried out by a licensed technician.
Ensure the following operations are carried out:
a) compliance of boiler parameters with (electricity, water, gas) supply
systems settings.
b) compliance of installation with the laws and regulations in force.
c) appropriate connection to the power supply and grounding of the
appliance.
Failure to observe the above will render the guarantee null and void.
Prior to commissioning remove the protective plastic coating from the
unit. Do not use any tools or abrasive detergents as you may spoil the
painted surfaces.
Commissioning of the boiler
To correctly light the burner proceed as follows:
1) provide power supply to the boiler;
2) open the gas cock;
3) turn the selector switch (1) to set the boiler on summertime ( ) or
wintertime ( ) operation;
4) turn the central heating (5) and domestic hot water (6) adjusting
controls in order to light the main burner.
To increase temperature values turn the control clockwise and
anticlockwise to decrease it.
When on summertime operation ( ) the main burner and the pump
will start running only when there is a call for hot water.
()
()
()

5
0209_3024
0210_0206
Figure 1
Figure 2
Warning: During initial lighting, until the air contained in the gas pipes
is not released, the burner may fail to light immediately and that may
cause a ‘blockage’ of the boiler. In this case we recommend you repeat
the ignition procedure until gas is delivered to the burner, setting selector
(1) to ( ) for at least 1 second (see also figure 4).
Room temperature adjustment
The system must be equipped with a room thermostat (see the relevant
regulations) to control the temperature in the rooms.
In case there is no room thermostat, during initial lighting it will be
possible to control the room temperature by turning control (5).
To increase temperature values turn the control clockwise and
anticlockwise to decrease it. Electronic modulation of the flame will
enable the boiler to reach the set temperature by adapting the gas supply
to the burner to the actual heat exchange demand.
DHW temperature adjustment
The gas valve is provided with an electronic flame-
modulating function, which operates depending on
the DHW temperature adjusting control (6) settings
and on the quantity of water drawn from the taps.
This electronic device allows to keep the water
coming out of the boiler at a constant temperature
also when small quantities of water are drawn.
To ensure energy saving and economical manage-
ment of your boiler, we recommend you place the
switch adjusting the hot water temperature on
“comfort” (see figure 2). In wintertime it will be
necessary to increase the DHW temperature
according to needs.
comfort zone
0403_0802

6
0210_0103/4/5
9909270100
Boiler filling tap Boiler drain valve
Figure 3
Filling the boiler
Important: Regularly check that the pressure displayed by the pressure
gauge (7) is 0.5 to 1 bar, with boiler not operating. In case of overpressure,
open the boiler drain valve.
In case the pressure is lower open the boiler filling tap (figure 3).
We recommend you open the tap very slowly in order to let off the air.
In case pressure drops occur frequently have the boiler checked by a
Qualified Service Engineer.
The boiler is supplied with a hydraulic differential pressure sensor, which
blocks the boiler in case water is lacking or the pump is blocked.
Turning off the boiler
To turn off the boiler turn the selector switch (1) on (0); you will thus
isolate the electrical supply to the boiler.
Prolonged standstill of the system.
Frost protection (central heating system)
We recommend you avoid draining the whole system as water
replacements engender purposeless and harmful limestone deposits inside
the boiler and on the heating elements.
In case the boiler is not operated during wintertime and is therefore
exposed to danger of frost we suggest you add some specific-purpose
anti-freeze to the water contained in the system (e.g.: propylene glycole
coupled with corrosion and scaling inhibitors).
Gas change
These boilers produced for natural gas can be converted to work with
LPG.
Any gas change must be effected by a Qualified Service Engineer.

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0312_1601
Figure 4 0209_3022
Safety device Indicators-
activation
1Summer-Winter-Reset selector
2Flame indicator
3Block indicator
4Voltage presence indicator
If safety device activation is repeated contact the authorised Technical
Assistance Service.
NOTE*
Slow flashing: comes on approximately once every 2 seconds
Fast flashing: comes on approximately twice a second
Servicing instructions
To maintain efficient and safe operation of your boiler have it checked
by a Qualified Service Engineer at the end of every operating period
.
Careful servicing will ensure economical operation of the system.
Do not clean the outer casing of the appliance with abrasive, aggressive
and/or easily flammable cleaners (i.e.: gasoline, alcohol, and so on).
Always isolate the electrical supply to the appliance before cleaning it
(see section Turning off the boiler on page 6).
Trouble
Gas block
No draught
No water in the heating circuit
or pump jammed
Probe broken
Safety thermostat tripping
Indicator
LED 2 LED 3
off on
off Fast flashing
off
Slow flashing
Slow flashing Slow flashing
on
Slow flashing
Reset
Set selector 1 to position R for at least 1 second.
Call your Authorised Service Centre
See circuit filling chapter
Call your Authorised Service Centre
Set selector 1 to position R for at least 1 second.

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0403_1101
Instructions pertaining
to the installer
0209_3021
General information
Warning: When the selector switch (1) is
set on Wintertime operation ( ) it may
be necessary to wait some minutes at each
intervention of the central heating tempera-
ture adjusting control (5). To relight the main
burner immediately place the selector switch
(1) on (0) and then again on ( ). No
waiting is needed when the boiler is in the
DHW mode on models with this option.
The following remarks and instructions are addressed to Service
Engineers to help them carry out a faultless installation. Instructions
regarding lighting and operation of the boiler are contained in the
‘Instructions pertaining to the user’ section.
Note that installation, maintenance and operation of the domestic gas
appliances must be performed exclusively by qualified personnel in com-
pliance with current standards.
Please note the following:
*This boiler can be connected to any type of double- or single feeding
pipe convector plates, radiators, thermoconvectors. Design the system
sections as usual though taking into account the available output /
pump head performances, as shown on page 23.
*Do not leave any packaging components (plastic bags, polystyrene,
etc.) within children’s reach as they are a potential source of danger.
*Initial lighting of the boiler must be effected by a Qualified Service
Engineer.
Failure to observe the above will render the guarantee null and void.
Instructions prior to installation
This boiler is designed to heat water at a lower than boiling temperature
at atmospheric pressure. The boiler must be connected to a central heating
system and, on models withis option, to a domestic hot water supply
system in compliance with its performances and output power.
Before connecting the boiler have the following operations effected:
a) careful checking that the boiler is fit for operation with the type of
gas available. For more details see the notice on the packaging and
the label on the appliance itself.
b) careful checking that the flue terminal draft is appropriate; that the
terminal is not obstructed and that no other appliance exhaust gases
are expelled through the same flue duct, unless the flue is especially
designed to collect the exhaust gase coming from more than one
appliance, in conformity with the laws and regulations in force
c) careful checking that, in case the flue has been connected to pre-
existing flue ducts, thorough cleaning has been carried out in that
residual combustion products may come off during operation of the
boiler and obstruct the flue duct thus engendering dangerous
situations.

9
To ensure correct operation of the appliance and avoid invalidating the
guarantee, observe the following precautions
1. Hot water circuit:
if the water hardness is greater than 20 °F (1 °F = 10 mg calcium carbonate
per litre of water) install a polyphosphate or comparable treatment system
responding to current regulations.
2. Heating circuit
2.1. new system
Before proceeding with installation of the boiler, the system must
be cleaned and flushed out thoroughly to eliminate residual thread-
cutting swarf, solder and solvents if any, using suitable proprietary
products.
2.2. existing system:
Before proceeding with installation of the boiler, the system must
be cleaned and flushed out to remove sludge and contaminants, using
suitable proprietary products.
To avoid damaging metal, plastic and rubber parts, use only neutral
cleaners, i.e. non-acid and non-alkaline (e.g. SENTINEL X400 and
X100), proceeding strictly in accordance with the maker’s directions.
Remember that the presence of foreign matter in the heating system can
adversely affect the operation of the boiler (e.g. overheating and noisy
operation of the heat exchanger)

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0011211100
The template to fix the boiler on
the wall
Decide upon the boiler location, then tape the template on the wall.
Connect the pipework to the gas and water inlets prearranged on the
template lower bar.
We suggest you fit two G3/4 stop cocks (available on demand) on the
central heating system flow and return pipework; the cocks will allow to
carry out important operations on the system without draining it
completely.
If you are either installing the boiler on a pre-existent system or
substituting it, we suggest you also fit settling tanks on the system return
pipework and under the boiler to collect the deposits and scaling which
may remain and be circulated in the system after the purge.
When the boiler is fixed on the template connect the flue and air ducts
(fittings supplied by the manufacturer) according to the instructions given
in the following sections.
0010171200
Figure 5
MR: G3/4 heating flow
US: G1/2 domestic hot water outlet
GAS: G3/4 gas inlet to the boiler
ES: G1/2 cold water inlet
RR: G3/4 heating return
Figure 6
9910070300
0209_3020
Boiler size

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0011211200
Installation of flue
and air ducts
We guarantee ease and flexibility of installation for a
gas-fired forced draft boiler thanks to the fittings and
fixtures supplied (described below).
The boiler is especially designed for connection to an
exhaust flue / air ducting, with either coaxial, vertical
or horizontal terminal. By means of a splitting kit a
two-pipe system may also be installed.
Exclusively install fittings supplied by the
manufacturer.
...coaxial flue - air duct (concentric)
This type of duct allows to disengage exhaust
gases and to draw combustion air both outside
the building and in case a LAS flue is fitted.
The 90°coaxial bend allows to connect the
boiler to a flue-air duct in any direction as it
can rotate by 360°. It can moreover be used as
a supplementary bend and be coupled with a
coaxial duct or a 45°bend.
(*) The restrictor must be removed in case the flue duct length exceeds
1,5 m.
If the flue outlet is placed outside, the flue-air ducting must protrude at
least 18mm out of the wall to allow alluminium weathering tile to be
fitted and sealed to avoid water leakages.
Ensure a 1 cm downward slope per each metre of duct length.
A 90°bend reduces the total duct length by 1 metre.
A 45°bend reduces the total duct length by 0.5 metre.
0209_3019
0010171400

12
Horizontal flue terminal installation options
L max = 5 m L max = 5 m
L max = 4 m
L max = 4 m
L max = 5 m
LAS flue duct installation options
0209_3018
0209_3017
0010171500

13
0010171700
L max = 4 m L max = 4 m L max = 3 mL max = 2 m
Vertical flue terminal installation options
This type of installation can be carried out both on a flat or pitched roof
by fitting a terminal, an appropriate weathering tile and sleeve,
(supplementary fittings supplied on demand).
For detailed instructions concerning the installation of fittings refer to
the technical data accompanying the fittings.
… separated flue-air ducting
This type of ducting allows to disengage exhaust flue gases both outside
the building both into single flue ducts.
Comburant air may be drawn in at a different site from where the flue
terminal is located.
The splitting kit consists of a flue duct adaptor (100/80) and of an air
duct adaptor; the latter may be placed either on the left or on the right of
the flue terminal according to installation requirements.
For the air duct adaptor fit the screws and seals previously removed
from the cap.
The restrictor must be removed in case you install separated flue and air
duct terminals.
The 90°bend allows to connect the boiler to flue-air ducting regardless
of direction as it can be rotated by 360°. It can moreover be used as a
supplementary bend to be coupled with the duct or with a 45°bend.
0209_3016
0010171600

14
(L1 + L2) max = 30 m (L1 + L2) max = 30 m
A 90°bend reduces the total duct length by 0.5 metre.
A 45°bend reduces the total duct length by 0.25 metre.
Separated horizontal flue terminals installation options
IMPORTANT: Ensure a minimum downward slope of 1 cm toward
the outside per each metre of duct length
In the event of installation of the condensate collection kit, the angle
of the drain duct must be directed towards the boiler.
L max = 10 m
NB: For C52 types, terminal for combustion air suction and combustion
product extraction must never be fitted on walls opposite the building.
The maximum length of the suction duct must be 10 metres.
If the flue duct exceeds 6 m, the condensate collection kit (supplied as
an accessory) must be fitted in the vicinity of the boiler.
0209_3015
0209_3014
0209_3013
0010171800

15
0010171900
L max = 14 m
L max = 15 m
Separated vertical flue terminals installation options
Important: if fitting a single exhaust flue duct, ensure it is adequately
insulated (e.g.: with glass wool) wherever the duct passes through
building walls.
For detailed instructions concerning the installation of fittings refer to
the technical data accompanying the fittings.
Split flue air control adjustment
The adjustment of this control is required to optimise performance and
combustion parameters. The air suction coupling which may be mounted
on the left or right of the flue duct can be rotated to adjust excess air
according to the total length of the flue and intake ducts for the combus-
tion air.
Turn this control clockwise to decrease excess combustion air and anti-
clockwise to increase it.
To improve optimisation a
combustion product analyser
can be used to measure the CO
2
contents of the flue at maxi-
mum heat output, gradually ad-
justing air to obtain the CO
2
reading in the table below, if the
analysis shows a lower value.
To properly install this device,
also refer to the technical data
accompanying the fitting.
0209_3012
0003170200
Figure 7
sx dx
0010172000
CO2%
(L1+L2) MAX
CONTROL POSITION G.20 G.30 G.31
0÷15 1
15÷30 2 6 7 7
—3

16
Figure 9
9402250715
Connecting the mains supply
Electrical safety of the appliance is only guaranteed by correct grounding,
in compliance with the applicable laws and regulations.
Connect the boiler to a 230V monophase + ground power supply by
means of the three-pin cable supplied with it and make sure you connect
polarities correctly.
Use a double-pole switch with a contact separation of at least 3mm in
both poles.
In case you replace the power supply cable fit a HAR H05 VV-F’
3x0.75mm2cable with an 8mm diameter max.
…access to the power supply terminal block
•isolate the electrical supply to the boiler by the double-pole switch;
•unscrew the two screws securing the control board to the boiler;
•rotate the control board;
•unscrew the screw securing the lid and gain access to the wiring (Fi-
gure
8).
A 2A fast-blowing fuse is in-
corporated in the power supply
terminal block (to check or replace
the fuse, pull out the black fuse
carrier).
(L) = Live brown
(N) = Neutral blue
() = Ground yellow/green
(1) (2) = room thermostat
terminal
Figure 8
0010172100
Fitting a room thermostat
•gain access to the power supply terminal block (Figu-
re 9) as described in the previous section;
•remove the jumper placed on terminals (1) and (2);
•insert the duplex cable through the core hitch and
connect it to the two terminals.
Connecting a programming clock
• remove the two screws securing the control board to the boiler and
hinge it downward;
•remove the 2 screws fixing the control board cover and hinge it
upward;
•connect the programming clock motor to the main PCB M3 connector
(terminals 18 and 20);
•connect the programming clock switch to the M3 connector terminals
(17 and 19) and remove the jumper.
In case you are fitting a battery-operated programming clock do not
connect the M3 connector terminals (18 and 20).
0402_0504

17
Gas change modalities
A Qualified Service Engineer may adapt this boiler to operate with natural
gas (G. 20) or with liquid gas (G. 30, G. 31).
The procedure for calibrating the pressure regulator may vary according
to the type of gas valve fitted (HONEYWELL or SIT; see figure 10).
Carry out the following operations in the given sequence:
A) substitute the main burner injectors;
B) change the modulator voltage;
C) proceed with a new max. and min. setting of the pressure adjusting
device.
A) Substitute the main burner injectors
•carefully pull the main burner off its seat;
•substitute the main burner injectors and make sure you tighten them
fast to avoid leakage. The nozzle diameters are specified in table 2.
B) Change the modulator voltage
•remove the 2 screws securing the control board cover and hinge it
upward;
•set the jumper or the switch, according to the type of gas used, as
described in the chapter on page 21.
C) Pressure adjusting device setting
•connect the positive pressure test point of a differential (possibly
water-operated) manometer to the gas valve pressure test point (Pb)
(Figure 10); connect, for sealed chamber models only, the negative
pressure test point of the manometer to a “T” fitting in order to join
the boiler adjusting outlet, the gas valve adjusting outlet (Pc) and the
manometer. (The same measurement can be carried out by connecting
the manometer to the pressure test point (Pb) after removing the sealed
chamber front panel);
If you measure the pressure of burners by different means you may
obtain an altered result in that the low pressure created in the sealed
chamber by the fan would not be taken into account.
SIT valve
mod. SIGMA 845
Figure 10
Honeywell valve
mod. VK 4105 M
99122215000207_0406
Pc
Pb
Pa
0402_0509
VK 4105 M

18
Figure 11
0207_0405
Honeywell gas valve SIT gas valve
a
a
b
b
Pc
C1) Adjustment to rated output
•open the gas tap and rotate knob (1) to set the boiler to the Winter
setting ( );
•open a hot water tap to reach a minimum 10 l/minute flow rate or
ensure that maximum heating requirements are set;
•remove the modulator cover;
•adjust the tube brass screw (A) Fig. 11 to obtain the pressure settings
shown at table 1;
•check that boiler feeding dynamic pressure, as measured at the inlet
gas valve pressure test point (Pa) (Figure 10) is correct (30 mbar for
G.30, 37 mbar for G.31, 20 mbar for natural gas);
C2) Adjustment to reduced heat output
•detach the modulator feeding cable and unscrew the (B) Fig. 11 screw
to reach the pressure setting corresponding to reduced heat output
(see table 1);
•connect the cable again;
•fit the modulator cover and seal.
C3) Final checks
•apply the additional dataplate, specifying the type of gas and settings
applied.
0402_0506

19
001121_1300

20
0403_0807
Control and operation devices
The boiler has been designed in full compliance with European reference
standards and in particular is equipped with the following:
•Central heating temperature adjustment potentiometer
This potentiometer sets the central heating flow max. temperature.
Its temperature range goes from 30 °C min. to 85 °C max.
To increase the temperature turn knob (5) clockwise and anticlockwise
to decrease it.
•Domestic hot water temperature adjusting potentiometer
This potentiometer sets the domestic hot water max. temperature. Its
temperature range goes from 35 °C min. to 65 °C max according to
the water inlet flow rate.
To increase the temperature turn knob (6) clockwise and anticlockwise
to decrease it .
•Air pressure switch
This switch allows the main burner to switch on provided the exhaust
flue duct efficiency is perfect.
In the event of one of the following faults:
•the flue terminal is obstructed
•the venturi is obstructed
•the fan is blocked
•the connection between the venturi and the air pressure switch is
not active
the boiler will remain on standby and LED 3 will flash at high
frequency.
The fan’s electric power supply is cut off if the air pressure switch
fails to provide a signal within a time of 10 minutes.
Momentarily move the selector ( 1 ) onto ( 0 ) to restore operation.
•Safety thermostat
This device, which is connected to a sensor on the central heating
delivery line, cuts off the flow of gas to the burner if the water in the
primary circuit overheats. In these conditions the boiler locks out
(LED 2 flashes slowly) and can be relit, by turning selector (1) to
position ( )for at least 1 second, only after the cause of the problem
has been removed.
Disabling this safety device is forbidden
•Flame ionization detector
The flame sensing electrode, placed on the right of the burner,
guarantees safety of operation in case of gas failure or incomplete
interlighting of the main burner.
Under such conditions the boiler is blocked (LED 3 illuminated).
Turn selector (1) to position ( ) for at least 1 second to restore
normal operating conditions.
If there is no gas, the unit makes 3 attempts at igniting the burner
with a 25-second pause between each attempt.
The unit shuts down if the burner fails to ignite after three attempts
(LED 3 illuminated).
0403_0805
0403_0806