Troubleshooting Manual

Quick Fault Finding Procedure

When troubleshooting your Potterton Promax Combi boiler please follow the following logical fault finding procedure

  1. Electrical Safety Checks. Check the electrical circuits by testing short circuit, earth continuity and resistance to earth tests. Check correct electrical polarity.
  2. Electrical Supply. Ensure that the boiler has electrical supply correct to 230 V.
  3. Gas Supply. Check the boiler has gas supply and that it has been purged. Ensure the boiler has an inlet gas pressure of 20 mbar at the gas valve.

Warning: Use only qualified Baxi Customer Support to work on Potterton gas boilers. All Baxi registered installers carry a BAXI identification card and have a registration number. 

  • Filling the Heating system. Ensure that the boiler is full of water and charged to 1.5-2.0 BAR.
  • Control. Ensure main on/off control is set to ‘on’
  • Temperature. Set the heating temperature to the maximum setting.
  • External Controls. Check that the external control display is calling for heat. Ensure that the boiler’s anti-cycling economiser is not engaging.

In an Emergency

If  you suspect  water or gas leak turn off the electrical supply and turn the selector switch on the facia box to the Off position, turn off the gas supply at the meter immediately and at the isolating valve on the boiler if possible. Call your customer support immidiately and request boiler specialist as soon as possible. Contact your Gas Supplier immediately.

Servicing your Appliance

For safety and economy reasons your boiler should be serviced annually. Your boiler specialist will be able to advise you.  Proper ventilation should be checked periodically  and electricity supply must be earthed. Standard 230V ~ 50Hz supply is required for all Potterton boilers. Never hang flammable items over the boiler.

Error codes

Potterton boilers will always display an error code to show what’s the issue. Please note that error codes only display if your system experiences one of the registered faults. These error codes will display in priority to all other information on the display.

The most common error codes are included in the table below:

Error Code Possible fault
E09 Gas valve wiring fault
E10 Outdoor sensor error
E15 Gas valave connection fault
E20 Central heating thermistor sensor fault
E28 Flue thermistor fault
E40 Central heating return thermistor fault
E50 Domestic hot water sensor fault
E53 Flue obstruction
E55 Calibration required
E78 Water pressure sensor fault
E83/84/85/86/87 No communication between room controller and boiler
E92 Combustion test alarm during auto-setting
E109 Poor circulation
E110 Boiler overheat tripped
E117 System pressure high (>2.9 bar)
E118 System pressure low (<0.5 bar)
E119 System pressure low (<0.5 bar)
E125 Primary water circulation fault
E128 Loss of flame during operation
E129 Loss of flame during calibration
E130 Flue thermostat sensor tripped (lockout)
E131 Flue overheat lockout
E133 Ignition fault
E135 Internal error
E151 PCB error
E152 PCB error
E154 Primary flow fault
E160 Fan fault
E161 Fan fault
E164 Domestic hot water sensor error (In the ROI this is a heating flow switch error)
E167 PCB fault
E168 PCB lock out
E193 Circulation
E270 Dry fire
E317 Wrong power supply (HZ)
E321 Hot water thermistor fault
E384 Flame detected when gas valve off (false flame)
E385 Low voltage (less than 195v)

The most common faults include, but not limited to:

1.table A- Potterton MAIN

Problem Cause Solution
Incorrect water temperature
Incorrect gas rate Check the gas supply to appliance gas isolation valve.

Open the gas isolation valve.

Check the burner pressure.

Check the inlet pressure.

Water section sticking or faulty. Clean or replace.
Incorrect water flow rate.
Incoming supply valve closed. Open supply valve.
Low water pressure. Check the water pressure is above 0.2 bar.
Water section sticking or faulty. Clean or replace.
Noise.
Scale in heat exchanger. Descale and service.
High gas rate. Check the burner pressure.
Low water flow rate. Check the water flow rate.

Pilot flame will not light or stay lit

No gas supply. Connect gas supply.
Gas isolation valve closed. Open gas isolation valve.
Air in gas line. Purge the line.
Pilot injector blocked. Clean/replace the injector.
No spark. Clean or replace the electrode, Piezo unit or cable.
Main burner will not light.
Gas pressure low. Check the inlet and burner pressure.
Gas isolation valve partially closed. Open the gas isolation valve.
Low water rate. Check the water rate.
Water section diaphragm faulty. Replace the diaphragm.
Gas valve faulty. Replace the gas valve.
Explosive ignition.
Reduced pilot flame. Clean or replace the pilot injector assembly.
Faulty slow ignition valve. Replace the slow ignition valve.

2. Table B- Potterton PERFORMA 24

fault1

 

fault 2

3. Table C- Potterton STATESMAN

Problem Cause Solution
Burner Does Not Start, Motor Does Not Run
Mains switched on Switch on
Fuse in switch Fit a fuse
Fuse blown Replace fuse
All external controls call for heat Set to call for heat
Boiler stat calls for heat Set to an “ON” position
Limit stat tripped – Light on Reset limit stat
Boiler at lock out – Light on Reset
Faulty external wiring Repair if necessary
Faulty external controls Check that they are operating
Burner Starts, No Flame Established, No Oil To Burner
Oil in the tank Re-Fill
All valves open from tank to burner Open valves
Fire valve correctly set Set as per manufactures instructions
Filter blocked Clean and replace elements
Air lock in fuel lines Bleed burner
Nozzle blocked Replace nozzle
Locks Out In orning Only
Combustion air setting too high Re-set and confirm by measuring
refer to Burner Instructions CO2
Air collects in system overnight Examine all joints and if suspect
re-make
Burner Runs But Smoke, and or Smell, and or
Pulsation
Correct grade of fuel used Either adjust for fuel used or drain and refill tank correctly
Correct nozzle fitted Refer to Burner Instructions and fit correct nozzle
Correct air settings Do combustion checks and re-set
Air in fuel lines Bleed air from lines
One sided flame Remove burner, clean and re-check settings, clean or replace the nozzle

4. Table C- Potterton OSPREY

electrical

Reseting Potterton boilers

All Potterton boilers can be reset. Resetting boilers with LED display should be performed when LED is showing continuous or flashing red. Normally it occurs when the boiler fails to light or the boiler is actually running, but the gas is turned off. To reset you need to press the reset button for a 1-10 seconds, after this LED will stop flashing and the boiler will attempt to re-light.

Attention!!! When LED display is flashing red very fast then the control is in remote diagnostic mode. The boiler will not work in this mode and will need to be reset again. You will need to press the reset button for 10 seconds, the LED will flash Orange once then return to normal operation.

In cases boiler doesn’t reset, check the error codes above and phone a boiler specialist to remove fault.

 

 

 

LED display

Led display 2

 

 

 

Repair and replacement parts

Potterton all boilers repair and replacement parts are being supplied by Baxi Genuine Parts. All parts are being sourced by same manufactures used for original assets production. This way it guarantees quality, reliability and safety. There is one year gy=guarantee for all ordered parts.

Currently Potterton boiler parts are being supported for all the products lifetime. Baxi  supports with providing you discounted parts  for all current models for the last 10 years. They have a stock of over 17.000 parts which pretty much guarantees parts supply all year round on a short notice. All spare parts are  compliant with Gas Safe Regulations. They are easy to install by a boiler specialist and are designed with the purpose of maintaining a boiler’s longevity.

Safety First!

Please Note: Use only qualified BAXI registered contractors to work on gas boilers.

Initial steps

  1. Before starting to work on Potterton boilers turn off the thermostat knob to O (Off) on the control panel cover (hinges down)
  2. When removing and replacing any parts that involve draining the system, close the boiler isolation valves and then drain the boiler using the presure gauge connection. It is forbiden to use the safety valve to drain the boiler. For all Dv Models: when removing and replacing any parts that involve draining the system, the manual lever is on the left hand side of the diverter valve must be moved to the ‘MID’ (manual override) position. Return it to its original position after the system has been filled and vented. Non-Dv Models with external diverter valve: When removing and replacing any parts that involve draining the system, it may be necessary to move a lever on the diverter valve, see manufacturers instructions for the particular valve. Return it to its original position after the system has been filled and vented.
  3. Always allow the boiler to cool and isolate the electricity supply.
  4. Always turn off the gas at the gas service cock.
  5. When removing any items containing water (Hoses, pipes etc) make sure they do not spill on electrical components.
  6. Always replace consumable parts like o-rings and gaskets with new parts
  7. Always conduct electrical check such as polarity, continuity and resistance to earth with a multimeter before and after any work

Warning! Always test for gas soundness after completing any exchange of gas carrying components and carry out functional checks of controls.

 

Replacement of any component requires the removal of the outer case front panel.  To remove it follow steps below:

1.Open control panel cover, remove the two screws (one each side) securing the control panel to the case side panels.

2. Carefully slide out the assembly away from the boiler, unclipping the neon from the back of the control panel before fully withdrawing the assembly.

Warning!: When a programmer is fitted, disconnect the wiring harness from the rear of the programmer before fully
withdrawing the bottom panel assembly.

3. Remove the outer case front panel by pulling it forwards off its fixings.

4. Place the case parts safely aside to avoid possible damage.

5. Re-assemble in reverse order

Pilot Injector replacement

1. Gain General Access -remove outer case front panel.

2. Pull the electrode lead off the electrode.

3. Undo the pilot supply pipe tubing nut at the pilot burner and gas valve. Remove the pilot injector.

4. Re-assemble in reverse order.

Main Burner replacement

1. Gain General Access – remove outer case front panel.

2. Pull the electrode lead off the electrode.

3. Undo the pilot supply pipe tubing nut at the pilot burner and gas valve. Remove the pilot injector.

4. Remove the two screws securing the right hand end of the burner to the chassis. Slide the burner to the right to

remove it from the main injector and withdraw the burner. While re-assembling  newthe pilot injector, position the injector over the end of the pilot supply pipe and carefully insert into the pilot burner.

5. Re-assemble in reverse order.

Burner 1

Pilot Burner replacement

1. Gain General Access – remove outer case front panel.

2. Pull the electrode lead off the electrode.

3. Undo the pilot supply pipe tubing nut at the pilot burner and gas valve. Remove the pilot injector.

4. Remove the two screws securing the right hand end of the burner to the chassis. Slide the burner to the right to

remove it from the main injector and withdraw the burner.

5. Remove the two screws securing the pilot burner to the main burner.

6. Re-assemble in reverse order.

Burner 2

Main Injector replacement

1. Gain General Access – remove outer case front panel.

2. Pull the electrode lead off the electrode.

3. Undo the pilot supply pipe tubing nut at the pilot burner and gas valve. Remove the pilot injector.

4. Remove the two screws securing the right hand end of the burner to the chassis. Slide the burner to the right to

remove it from the main injector and withdraw the burner.

5. Unscrew the main injector from the burner manifold and remove the sealing washer. While re-assembling main injector, use a suitable sealing compound on the threads and also use a new sealing washer. On re-assembly of the spark electrode check the spark gap. It should be 3 to 4mm.

6. Re-assemble in reverse order.

Fan replacement

1. Gain General Access -remove outer case front panel.

2. Disconnect the overheat thermostat leads.

3. Remove screws (two) securing the fan assembly to the flue hood. Slide the fan assembly away

from the flue to disengage the flue tube sleeve from the flue. Withdraw the fan assembly, disconnecting the fan

motor leads and pressure switch tube.

Note: If a Vertex or Vertical Flue is fitted, slide the flue tube sleeve up into the flue to disengage it from the fan outlet.

4. Remove screws (four) securing the fan to the diverter and remove the fan. Remove the flue tube sleeve from

the old fan. Make sure that the ‘O’ ring is in position on the fan outlet, then fit the flue tube sleeve over the fan

outlet and push it fully fits. Screw the new fan to the diverter (four screws).

5. Place the fan assembly on top of the flue hood with the outlet facing towards the flue. Re-connect the two violet

leads (polarity not important) to the fan motor and the air pressure tube to the fan.fan 1

6. With the fan assembly resting on the flue hood engage the flue tube sleeve on the fan outlet into the inner tube

of the flue. Make sure that the base of the fan assembly is located under the returns at the rear of the flue hood.

Note: If a Vertex or Vertical Flue is fitted, slide the flue tube sleeve down out of the flue and over the fan outlet.

7. Secure the front of the fan assembly to the flue hood with the two screws previously removed.

8. Re-assemble the boiler in reverse order.

 

 

fan 2

 

 

Gas valve replacement

1. Gain General Access -remove outer case front panel.

2. Disconnect the gas valve electrical plug from the valve.

3. Disconnect the pilot supply from the top of the gas valve.

4. Remove the four 3 mm socket screws securing the gas valve to the burner manifold.

5. Remove the screw securing the inlet manifold to the side of the chassis.

6. Undo and disconnect the union at the gas service cock and withdraw the gas valve. Remove and discard the ‘O’ ring in the burner manifold.

7. Remove the four 3 mm socket screws securing the inlet manifold and fit it to the new valve, using a new ‘O’ ring
(both ‘O’ rings are the same). With a new ‘O’ ring in the burner manifold secure the new valve to the manifold using the four socket screws previously removed.

9. Reconnect the pilot supply, gas service cock union, plug and secure the inlet manifold to the chassis.

10. Open the gas service cock and test the union and inlet manifold to gas valve connection for gas soundness.

12. Re-assemble the boiler in reverse order.

gas valve

Gas tap replacement

1. Gain General Access -remove outer case front panel.

2. Pull the control knob off the gas tap.

3. Remove the two screws securing the bezel around the tap. Remove the bezel.

4. Pull the electrode lead off the piezo unit.

5. Unscrew the thermocouple from the rear of the gas tap.

6.  Disconnect the three union nuts at the gas tap.

7. Remove the two gas tap screws and withdraw the gas tap.

8. Re-assemble the boiler in reverse order.

gas tap

Warning! Ensure the electrode lead is positively located. The thermocouple connection need only be finger
tight and a quarter turn. Check for gas soundness and correct operation of the fire.

Overheat Thermostat replacement

1. Gain General Access -remove outer case front panel.

2. Disconnect the wires from the thermostat.

3. Unscrew the thermostat from the pipe.

4. Re-assemble the boiler in reverse order.

thermostatjpg

Combustion Chamber Insulation replacement

1. Gain General Access -remove outer case front panel.

2. Remove the burner/gas valve assembly.
2. Remove combustion chamber front cover – two screws.

Warning!To avoid release of dust and fibrous material the insulation material should be dampend before removal.

3. Pull both sides of the combustion chamber inwards to unclip and pull forwards out from he boiler. Replace
insulation pieces as required, replace any securing clip if damaged.

4. Re-assemble the boiler in reverse order.

combustion

Electronic Control Board replacement

1. Gain General Access -remove outer case front panel.

2. Disconnect all connectors and wires, unscrew the two securing screws and remove the board.

3. Re-assemble the boiler in reverse order.
 Air Pressure Switch replacement

1. Gain General Access -remove outer case front panel.

2. Remove the securing screws and allow the control panel to pivot forwards

3. Note the wire connections and disconnect the wires to the air pressure switch.

4. Remove the screws securing the air pressure switch to the bracket.

5. Note the tube connections and remove the tubes from the switch.

6. Re-assemble in reverse order.

last ones
Temperature Sensor replacement

1. Gain General Access -remove outer case front panel.

2. Disconnect the wires from the sensor.

3. Depress the clips on the outside of the sensor and pull it clear of the heat exchanger.

4. Re-assemble in reverse order, use fresh conducting paste.

Central Heating and Boiler Switches replacement

1. Gain General Access -remove outer case front panel.

2. Wire routing and switch orientation, disconnect the molex plug from the electronic control board.

3. Using a small screwdriver press the retaining lugs on the switch body sides inwards and remove the switch from

the control panel. Withdraw the switch and leads and feed the molex plug through the cut out in the panel

4. Fit new switch assembly and re-assemble in reverse order. Ensure that the switch is the correct way round in

the panel i.e. when the Stand-by/On switch is On, the red indicator line on the switch can be seen.

5. Re-fit the molex plug to the correct plug position on the electronic control board.

6. Re-assemble in reverse order.

central heaters

Temperature Sensor D.H.W. & C.H. replacement

1. Gain General Access -remove outer case front panel.

2. For D.H.W sensor lower the control panel assembly by undoing the securing screw at the top right hand side of

the control panel.

3. Before removing the hot water or central heating sensor, first close the isolating valves for the circuit involved and

drain the appliance.

Warning! For C.H, with both 22mm isolating valves closed, reduce the system pressure by opening the pressure relief valve and drain the water from the heating circuit by removing the drain plug from the undersideof the pump manifold.

For D.H.W, close the 15mm cold water isolating valve,open the lowest hot water tap, then remove theD.H.W drain screw on the isolation valve to fully drain the appliance.

4. Disconnect the electrical connection from the sensors and unscrew from its housing.

5. Refit the new sensors and ‘O’ Ring seal if required.

6. Re-assemble in reverse order.
Warning! If necessary (C.H. sensor only) re-charge the central heating system and check for leaks.

Microswitch (D.H.W FLOW SWITCH) replacement

1. Gain General Access -remove outer case front panel.

2. Lower the control panel assembly by undoing the securing screw at the top right hand of the control panel.

3. Note the position of the electrical connections and remove the two wires from the micro switch.

4. Loosen the locknut and remove the switch, fit the new micro switch (with locknut) to the flow switch and position the switch s shown on the picture.

5. Re-assemble in reverse order. Ensure the wires are connected correctly as shown on the picture.

microswitch

 Diverter Valve replacement

The diverter valve is made up in two parts. The wax capsule head forms one part and provides the motive power to open the valve. The second part, the valve consists of the change over mechanism and the valve seating. It is likely that only replacement of the head will be necessary, if the complete valve requires replacement proceed to part 2.

Part 1. Wax Capsule Head replacement

1. Gain General Access -remove outer case front panel.

2. Lower the control panel assembly by undoing the securing screw at the top right hand side of the control panel.

3. Close the 15mm cold water isolating valve, open the lowest hot water tap and remove the D.H.W drain screw in the isolating valve to drain the system.

4. Close the central heating isolating valves, reduce the system pressure by opening the pressure relief valve and drain the water from the heating system by removing the drain plug from the underside of the pump manifold.

5. Undo the two D.H.W pipe connections to the valve head. Retain the two pipe seals.

6. Unscrew the two grub screws (2mm hexagon key) which hold the head to the main body. Pull the head forwards using a twisting action and carefully remove the head. Note the position of the loose brass cylinder on the wax capsule push rod and transfer onto new head assembly.

7. Fit new wax capsule head.

8. Re-assemble in reverse order. Replace pipe seals is necessary.

Wax capsule

Part 2. Complete valve replacement

1. Gain General Access -remove outer case front panel.

2. Lower the control panel assembly by undoing the securing screw at the top right hand side of the control panel.

3. Close the 15mm cold water isolating valve, open the lowest hot water tap and remove the D.H.W drain screw on the isolating valve to drain the system.

4. Close the central heating isolating valves, reduce the system pressure by opening the pressure relief valve and drain the water from the heating system by removing the drain plug from the underside of the pump manifold.

5. Undo the two D.H.W pipe connections from the head of the diverter valve. Retain the pipe seals.

6. Undo the Central heating pipe connections to the diverter valve body and loosen the two nuts retaining the C.H. Flow and Return pipe tails.

7. Remove the locknut at the rear of the diverter valve holding the valve to the front cross brace.

8. Undo connection to the pump manifold and withdraw the diverter valve from the boiler.Transfer the water pressure switch and drain cock to the new valve.

9.  Re-assemble in reverse order.

diverter valve 2

Boiler outer case front panel reassembly after parts replacement

1. Ensure that the inner case seals are intact and in position in the seal housing channels and that the channels are correctly located over the sides of the boiler chassis.

2. Replace the inner case front panel (expansion vessel frame fixing brackets nearest the top), securing it in position with the four screws previously removed. Tighten sufficiently to form a seal.

3. Remove the split pins from the ends of the tie rods and unhook them from the support frame, raise the expansion vessel assembly and secure the frame to the inner case front panel using the two screws previously removed.

4. Unhook the tie rods from the sides of the boiler, replace the split pins into the rods and position them in the retaining clips on the front of the expansion vessel frame.

5. Raise the control box and secure in position with the screw previously removed.

front panel