Potterton boiler fault codes

Promax Combi, System, and Store Error Codes

Fault Codes Possible Cause 
E10Outdoor sensor error
E20Central heating thermistor sensor fault
E28Flue thermistor fault
E50Domestic hot water sensor fault
E110Boiler overheat tripped
E119System pressure too low
E125Primary water circulation fault
E130Flue thermostat sensor tripped (lockout)
E131Flue overheat lockout
E133Ignition fault. If you have a prepayment meter, please check the meter to ensure that the supply is ON because it might simply be that you have ran out of gas and need to top-up, then reset the boiler.
E151Printed circuit board (PCB) error
E152PCB error
E160Fan fault
E161Fan fault
E164Domestic hot water sensor error – could be a heating flow switch error)
E167Printed circuit board (PCB) fault
E168Printed circuit board (PCB) lockout
E193Circulation

Potterton Promax Ultra, Gold/Titanium Combi & System Boiler Error Codes

Fault CodePossible Cause 
E09Gas valve wiring fault
E10Outdoor sensor error
E15Gas valve connection fault
E20Central heating thermistor sensor fault
E28Flue thermistor fault
E40Central heating return thermistor fault
E50Domestic hot water sensor fault
E53Flue obstruction
E55Calibration required
E78Water pressure sensor fault
E83 / 84 / 85 / 86 / 87No communication between room controller and boiler
E92Combustion test alarm during auto-setting
E109Poor circulation
E110Boiler overheat tripped
E117System pressure too high (>2.9 bar)
E118System pressure too low
E125Primary water circulation fault
E128Loss of flame during operation
E129Loss of flame during calibration
E130Flue thermostat sensor tripped (lockout)
E133Ignition fault
E135Internal error
E154Primary flow fault
E160Fan fault
E270Dry fire
E317Wrong power supply (HZ)
E321Hot water thermistor fault
E384Flame detected when gas valve off (false flame)
E385Low voltage (less than 195v)

Potterton Assure Combi and system Boiler Error Codes

Fault CodePossible Cause
E09Gas valve connection cable fault
E10External probe fault
E12Differential water flow switch is still open
E13Differential water flow switch is still closed
E15Fault with the gas valve command
E20Central heating negative temperature coefficient (NTC) fault
E28Flue negative temperature coefficient (NTC) fault
E40Central heating return negative temperature coefficient (NTC) fault
E50Domestic hot water (DHW) negative temperature coefficient (NTC) sensor (tank boiler) (s.c) or DHW NTC sensor (tank boiler) (o.c.) Fault
E83 / E84 / E85 / E86 / E87Communication error
E109Pre-circulation fault
E110Boiler Max temperature exceeded for gradient (or overtemperature) Probable pump jammed or air in the circuit or Safety thermostat sensor tripped
E118Primary system water pressure too low
E125Primary circulation fault
E128Flame failure (12 times)
E129Frequent loss of flame (safety error)
E130Flue thermostat sensor tripped and locked out
E133Possible gas supply issue (failure to light)
E134Elapsed time gas valve open without gas
E135Internal error (interruption of gas supply)
E154Flow/return sensor temperature test
E160Problem with fan (possible wiring fault)
E163Domestic hot water (DHW) negative temperature coefficient (NTC) sensor fault (s.c.) or DHW NTC sensor fault (o.c.)
E270Dry fire
E317Wrong power supply (HZ)
E321Hot water fault
E384False flame
E385Under voltage
E430Water pressure test
E430 + Flame crossedWater pressure test failed