2023 Keston Boiler Error & Fault Codes
A Keston boiler error code will require an inspection of the problem identified by the code. There are various codes and steps that need to be followed in order to identify the exact problem with the boiler from a more extensive list of problems. The Keston error code guide will help you familiarize yourself with the simplest to most difficult boiler error codes, so you know what steps to take next.
When diagnosing a problem with Keston boilers, it is very important to first identify the error code that displays on the LEDs. The error code will indicate where the fault lies within the boiler or system and grant engineers will send out an engineer to take a look at it. The engineers are highly trained and they will identify the fault and resolve it in an efficient manner.
C36 Combi Gas Boiler Error Codes
Keston combi boiler error codes are an important part of your boiler maintenance. If you don't check your Keston C36 combi boiler error codes, you may end up with problems down the line. Error codes will help to prevent costly breakdowns and unexpected bills. In this table we'll teach you how to manually read your fault code and give you some top tips on what to do if you have any problems identifying the code.
| Fault Code | 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 |
S30 System Gas Boiler Error Codes
Keston S30 System Gas Boiler Error Codes. As boiler breakdowns can cost you money, we’ve compiled the list of error codes to help you get your boiler back up and running as quickly as possible. With the amount of time it takes for a professional engineer to come around, this is an easy way for you to be able to potentially fix issues and avoid wasting more money on call-out charges and parts.
| Fault Code | 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 |
C40 C55 Combi Gas Boiler
Keston C40 and C55 combi boilers are widely used for space heating but also for domestic hot water when the combi boiler is used alone. One of the common faults seen in these Keston boiler is a flashing fault indication on the control panel - this boiler fault code can be very difficult to interpret.
This table explains how to decode error codes for Keston C40 Gas Combination Boilers, and the Keston C55 Gas combination boiler.
| Fault Code | 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 |
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