Do you have a Keston boiler?
If it’s not performing as it should and you can’t find the manual, there’s no need to worry. Below we’ve provided (almost) all of the Keston boiler error codes to help you suss out what’s wrong.
If you can’t see your boiler’s error code, or don’t understand the possible cause and what you need to do about it, you can book a 15-minute video call at Herofix.com to receive expert advice from a qualified professional.
Before we dive into the meaning of the various Keston boiler error codes, remember that an unqualified person is not permitted to remove a boiler’s case, unscrew any of its panels or remove any of its parts. This applies even when you’re certain you know what you’re doing!
Keston boilers we have covered in this error code list:
Keston C36 Combi Gas Boiler Error Codes
Error | Possible Cause |
---|---|
E01 | Ignition failure – the boiler has attempted to light 5 times and not succeeded – check the gas supply is on |
E02 | False flame – possibly a problem with the power supply |
E03 | Boiler overheat – check that any valves to the heating circuit have not been shut down, no air in the system and that the water pressure is correct |
E05 | Fan failure – boiler cannot detect fan rotation – check fan operation and both connectors onto fan |
E07 | Flue overheat – check combustion and flue temperature vs. return temperature – the flue temperature should be no more than 10C above return temperature. Possible heat exchanger fault. |
E08 | Flame circuit error – possible control box fault |
E09 | Valve drive error – possible gas valve or control box fault |
E10 | Control box errors – possible faulty control box |
E11 | The automatic test for calibration of flow and return sensors has failed – check both flow and return sensors are located on the correct pipes and are producing the correct readings |
E12 to E22 | Control box errors – possible faulty control box |
E23 | Water filling error – check water pressure sensor |
E24 | Water pressure lost 4 times in 24 hours – possible leak, check system and boiler |
E25 | Control box errors – possible faulty control box |
E26 | Flame drop out – check for obstruction of the flue and/or air terminals, blockage/freezing of the drain pipe or a low gas supply (LPG). |
E30 | Flow sensor short circuit – check connections to flow sensor |
E31 | Flow sensor open circuit – check connections to flow sensor are in place |
E32 | DHW sensor short circuit – check connections to domestic hot water (DHW) sensor |
E33 | Domestic hot water (DHW) sensor short circuit – check connections to DHW sensor are in place |
E34 | Mains supply voltage < 180V – may be a problem with your power supply |
E35 | Mains supply frequency incorrect – may be a problem with the power supply |
E37 | Water pressure error – increase the system water pressure |
E38 | Reset key fault – replace fascia PCB |
E40 | Water pressure too high |
E41 | Communication error between fascia and control box – check cables |
E43 | Return sensor short circuit – check connections to return sensor |
E44 | Return sensor open circuit – check connections to return sensor are in place |
E45 | Flue sensor short circuit – check connections to flue sensor |
E46 | Communication error between fascia and control box – check cables |
E99 | Flue sensor short circuit – check connections to flue sensor are in place |
Keston S30 System Gas Boiler Error Codes
Error | Possible Cause |
---|---|
0 | The boiler is in standby mode awaiting either a central heating call or hot water demand |
C | The boiler has a call for central heating / hot water but the appliance has reached the desired temperature set on the boiler |
C And Burner Light | The boiler is operating for central heating / hot water |
F And Burner Light | The boiler is operating in frost mode |
F0 | Boiler Chip Card (BCC) not fitted |
F6 | Outside sensor failure |
F7 | Low mains voltage |
F9 | Printed circuit board (PCB) Fault |
L5 | 5 boiler resets in 15 minutes |
L6 | False flame lockout |
C0 | Boiler Chip Card (BCC) activation fault |
C2 | Boiler Chip Card (BCC) fault |
F1 | Low water pressure |
L1 | Flow temperature overheat |
F2 | Flame loss |
L2 | Flame loss |
F3 | Fan fault |
F4 | Control / No flow thermistor |
F5 | Return thermistor |
Keston C40 C55 Combi Boiler
Error | Possible Cause |
---|---|
Enn | Fault causing a boiler shutdown |
E00 | Flame detected when not expected – check boiler earth and probe condition |
E02 | No ignition after restart – check gas supply, gas valve operation and ignitor electrode spark generation |
E03 | Gas valve faulty or not connected |
E04 | Power has been reset whilst boiler was in lockout |
E11 | Internal electronics error – rest or replace control box |
E18 | Flow overheat – check water circulation |
E19 | Maximum return temperature exceeded – check circulation |
E25 | Flow temperature increased too quickly – check water circulation |
E30 | Difference between flow and return temperatures too high – check circulation. |
E31 | Flow thermistor short circuit – check/replace connections/thermistor |
E32 | Return thermistor short circuit – check/replace connections/thermistor |
E36 | Flow thermistor open circuit – check/replace connections/thermistor |
E37 | Return thermistor open circuit – check/replace connections/thermistor |
E44 | Low water pressure |
Not sure what to do next? No problem! You can book at 15-minute video call to get expert advice at Herofix.com.