2024 Main Boiler Error & Fault Codes
This article covers all the error codes that you may encounter with your Main boiler. We have compiled this guide to be used as a reference for engineers, heating contractors and other service engineers who are looking for error code information during an installation, service call or fault finding session.
If your Main boiler has stopped producing hot water or is showing any of the error codes listed, you can probably solve the problem quickly and easily. The first thing you should do, however, is check that there hasn't been an interruption to either your mains power supply or the control supply for your boiler.
Main boiler error codes are split into two sections. One is general and the other is specific to your model of boiler. Below you'll find easy to follow error code definitions. Error codes that are specific to a particular model, such as the Eco Compact.
General Main Boiler Error Codes
Main boiler error codes sometimes appear on the display when you turn the boiler on to heat up your central heating system. Commonly, a fault will cause the boiler to light up with an error code as soon as it is switched on. The codes that appear are usually quite clearly written so it is easy to tell what the problem is and how to fix it.
General Main error codes or fault codes are helpful to the technicians in finding and resolving the issues with household boilers.
| Fault Code | Possible Cause |
|---|---|
| E168 | Error code E168 could mean that your boiler has detected a problem but can’t work out exactly what it is; |
| E20 | "Central Heating NTC Fault indicate faulty components. You |
| E28 | PCB Fault indicate faulty components |
| E50 | Hot Water NTC Fault indicate faulty components |
| E110 | Safety Thermostat operated – displayed when the primary water pressure is less than 0.5 bar. After repressurising the system the boiler should operate. Your installer will be able to advise you about the method of repressurising. |
| E119 | "Water pressure switch not operated – displayed when the primary water pressure is less than 0.5 bar. After repressurising the system the boiler should operate. Your installer will be able to advise you about the method of repressurising" |
| E33 | Interruption Of Gas Supply or Flame Failure indicates that the gas supply has been interrupted, ignition has failed or the flame has not been detected. Ensure that the gas supply has not been turned off, and turn the selector switch to the reset position and hold for at least 5 seconds. If the boiler does not relight, or the code is displayed regularly. |
| E60 | Fan or fan wiring fault |
Main Eco Compact Boiler Error Codes
The error codes below are the error codes that may appear on the display when the boiler stops or when there is a fault with the Eco Compact.
These codes are applicable to all Main Eco Compact Boiler models. Error codes can be displayed in any of three ways, via the EPS, the LED display or via the control panel mounted push button switches or any combination thereof.
The Eco Compact boiler error codes in this table are universal. That means that they should work for all versions of the Eco Compact boilers that support digital diagnostics.
| Fault Code | Possible Cause |
|---|---|
| E09 | Gas valve connection error |
| E15v | Gas valve error |
| E20 | Central heating negative thermistor coefficient (NTC) sensor error |
| E28 | Flue negative thermistor coefficient (NTC) sensor error |
| E40 | Central heating return sensor error |
| E83 | Communication error |
| E109 | Pre-circulation fault |
| E110 | Safety thermostat operated |
| E118 | Primary system water pressure too low |
| E125 | Circulation error |
| E128 | Flame error |
| E130 | Flue negative thermistor coefficient (NTC) sensor operated |
| E133 | Interruption of gas supply or flame error |
| E135 | Interruption of gas supply |
| E154 | Flow return sensor temperature test |
| E160 | Fan or fan wiring error |
| E270 | Circulation fault (dry fire) |
| E321 | Hot water negative thermistor coefficient (NTC) error |
| E384 | False flame |
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