- Keston Boiler Error Codes
Keston Boiler Error Codes
Listed below are Keston boiler fault codes and Keston boiler Manuals.
Fault Description
|
Possible Cause
|
---|---|
E01 | Ignition failure – the boiler has attempted to light five times and not succeeded – check the gas supply is on |
E02 | False flame – There is possibly a problem with the power supply |
E03 | Boiler overheat – Check that any valves to the heating circuit have not been shut down, that there is 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 (Installer numbers 7 and 3 above). 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 DHW sensor |
E33 | DHW sensor short circuit – check connections to DHW sensor are in place |
E34 | Mains supply voltage < 180V – There may be a problem with your power supply |
E35 | Mains supply frequency incorrect – There may be a problem with your power supply |
E37 | Water pressure error – You must top up the water pressure for your system |
E38 | Reset key fault – replace fascia PCB |
E40 | Water pressure too high – You have put too much water pressure in your system |
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 |
- To get your Keston Boiler Repaired, call us today on Cardiff 02920 140240

Fault Description
|
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 | PCB Fault |
L5 | 5 Boiler Resets in 15 minutes |
L6 | False Flame Lockout |
C0 | BCC Activation Fault |
C2 | 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 |
- To get your Keston Boiler Repaired, call us today on Cardiff 02920 140240

Fault Description
|
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 |
- To get your Keston Boiler Repaired, call us today on Cardiff 02920 140240

- Call for a Boiler repair today on Cardiff 02920 140240
Call for a Boiler repair today on Cardiff 02920 140240

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