When your Potterton boiler develops a fault, an error code or fault code should appear on your boiler display. These fault codes are designed to make it easy for your engineer to diagnose and fix issues with your Potterton boiler, so make sure you tell your engineer the fault code when you contact them to arrange a repair. You may be able to clear the fault yourself if it’s something really simple like resetting the boiler but the majority of faults will need to be sorted out by a qualified heating engineer.
If a fault code has appeared on your Potterton boiler, take a look at the tables below to find out what the code means.
Potterton Assure Combi Boiler Fault Codes
Fault Code
Description / Possible Cause
E09
Gas valve connection cable.
E10
External probe fault.
E12
Differential water flow switch fault (still open).
E13
Differential water flow switch fault (still closed).
E15
Gas valve command fault.
E20
Central heating NTC fault.
E28
Flue NTC fault.
E40
Central heating return NTC fault.
E50
Domestic hot water (DHW) NTC sensor fault (tank boiler) (s.c.) or DHW NTC sensor fault (tank boiler) (o.c.).
E83, E84, E85, E86 or E87
No communication.
E190
Pre-circulation fault.
E110
Boiler max temperature exceeded for gradient (could be a jammed pump or air in the circuit) or boiler maximum temperature exceeded for overtemperature (could be jammed pump or air in the circuit) or the safety thermostat has tripped.
E118
Primary system water pressure is too low.
E125
Circulation fault (primary).
E128
Frequent flame failure – 12 times.
E129
Safety error for frequent loss of flame with maximum correction during the ignition during calibration function.
E130
Flue thermostat sensor has tripped (lockout).
E133
Failure to light (could be an issue with gas supply). Check that the gas supply is available by lighting your gas fire or cooker.
E134
Elapsed time gas valve open without gas (short request in a short period).
E135
Interruption of gas supply (internal error).
E154
Flow/return sensor temperature test.
E160
Fault with fan or fan wiring.
E163
Domestic hot water (DHW) NTC sensor fault (s.c.) or DHW NTC sensor fault (o.c.).
E270
Circulation fault (dry fire).
E317
Wrong power supply electrical frequency (Hz).
E321
Hot water NTC fault.
E384
False flame.
E385
Under voltage.
E430
Water pressure temporary test.
E430 + flame crossed
Water pressure test failed.
Potterton Promax Ultra Boiler Fault Codes
Fault Code
Description / Possible Cause
E09
Gas valve wiring fault.
E10
Outdoor sensor error.
E15
Gas valve 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, E84, E85, E86 or E87
No communication between boiler and room controller.
E92
Combustion test alarm during auto-setting.
E109
Poor circulation.
E110
Boiler overheat has tripped.
E117
System pressure too high.
E118
System pressure too low.
E125
Primary water circulation fault.
E128
Loss of flame during operation.
E129
Loss of flame during calibration.
E130
Flue thermostat sensor has tripped (lockout).
E133
Ignition fault.
E135
Internal error.
E154
Primary flow fault.
E160
Fault with fan.
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.
Potterton Promax Combi, System and Store Boiler Fault Codes
Fault Code
Description / Possible Cause
E10
Outdoor sensor error.
E20
Central heating thermistor sensor fault.
E28
Flue thermistor fault.
E50
Domestic hot water sensor fault.
E110
Boiler overheat has tripped.
E119
System pressure too low.
E125
Primary water circulation fault.
E130
Flue thermistor sensor has tripped (lockout).
E131
Flue overheat lockout.
E133
Ignition fault.
E151 or E152
PCB error.
E160 or E161
Fault with fan.
E164
Domestic hot water sensor error (UK) or heating flow switch error (ROI).
E167
PCB fault.
E168
PCB lockout.
E193
Circulation error.
Potterton Gold Combi, Gold System and Titanium Combi Boiler Fault Codes
Fault Code
Description / Possible Cause
E09
Gas valve wiring fault.
E10
Outdoor sensor error.
E15
Gas valve 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, E84, E85, E86 or E87
No communication between boiler and room controller.
