If your Main boiler is flashing a fault code, chances are you’re standing there frustrated, wondering what’s gone wrong and how much it will cost. Don’t worry, you’re not alone.
This guide breaks down the most common Main boiler error codes so you can quickly identify the issue and decide what to do next. Whether you own a Main Eco Compact Combi, System, or Heat Only model, we’ve got you covered.
Main boilers are generally known for being affordable, easy to install, and Energy Saving Trust endorsed—but like all boilers, they can run into problems over time. If yours has packed in or keeps throwing up error messages, this blog will help you:
- Understand what each error code means
- Know when it’s something simple, you can check
- Know when to call a Gas Safe Engineer
- Decide if it might be time for a boiler replacement
If you’re tired of breakdowns and considering a new boiler, WarmZilla can help you get a fixed price quote in under 2 minutes with our online boiler survey.
Let’s examine the error codes for Main boilers so you can get back to heating your home without the guesswork.
Main Boiler Error Codes
| Fault Code | System Behaviour |
|---|---|
| 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 indicates faulty components. You should make a note of the displayed error code. |
| E28 | PCB Fault indicates faulty components. |
| E50 | Hot Water NTC Fault indicates 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. This 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, call a Gas Safe Engineer. |
| E60 | Fan or fan wiring fault. |
Main Eco Compact Boiler Error Codes
| Fault Code | System Behaviour |
|---|---|
| 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 |
Main Error Code E133
If your Main boiler is showing the error code E133 means that the condensate pipe has frozen. This is an issue that can happen during the cold winter months as the condensate pipe leads outside but luckily this is an issue that can be resolved fairly quickly without the need for an engineer. If you want to learn more about how to unfreeze your condensate pipe, we have a blog that might help you out ??
This is probably the best time to mention that WarmZilla has a Best Price Guarantee offer that ensures that we will beat any boiler price by £50 if you manage to find a boiler cheaper elsewhere (which you won’t).
Boiler Manuals
Thanks to our friends over at freeboilermanual.com, we have linked all the Main boiler manuals below, just in case you need that little extra help on understanding your boiler and how it works ??
- Main combi 25 eco
- Main combi 30 Eco
- Main combi 24HE
- Main combi 30HE
- Main 9 HE
- Main 12 HE
- Main 15 HE
- Main 18 HE
- Main 24 HE
- Main ECO Elite Combi 25 ErP
- Main ECO Elite Combi 30 ErP
- Main Eco Compact Combi 25
- Main Eco Compact Combi 30
- Main Eco Compact Heat 15
- Main Eco Compact Heat 18
- Main Eco Compact Heat 24
- Main Eco Compact Heat 30
- Main Eco Compact System 15
- Main Eco Compact System 18
- Main ECO Elite System 24 ErP
- Main ECO Elite System 29 ErP
- Main Multipoint FF
- Main System 18HE
- Main System 24HE
- Main System 28HE
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