17 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Tap any card for details
Your boiler is still providing hot water, but the central heating is not turning on when it should.
Your boiler is providing central heating to your home, but it is not currently producing hot water for your taps and showers.
Your boiler has completely lost power and the screen is blank, meaning it is not currently working.
Your boiler has detected an issue with its internal combustion control system and has safely locked itself out to prevent unsafe operation.
Your boiler has lost communication with its internal memory chip, meaning it cannot safely control your heating and hot water.
Your boiler has stopped working because a small electronic identification chip is either missing or has not been properly set up on the control board.
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler's flame has unexpectedly gone out while trying to run, which safely shuts down the system.
Your boiler has detected an issue with the internal fan that safely removes combustion gases, causing it to lock out for safety.
Your boiler has detected a problem with the sensor that measures the temperature of the water flowing through the system, causing it to stop working for safety.
Your boiler has temporarily stopped working because a sensor measuring the temperature of the water returning to the system is sending an incorrect reading.
Your boiler has temporarily stopped working because the electrical supply from your home mains voltage has dropped below the safe operating level.
Your boiler's main electronic brain has experienced a critical internal error and has safely shut down to prevent further issues.
Your boiler has temporarily locked itself out for safety after registering too many automatic resets in a short space of time.
Your boiler has mistakenly detected a flame inside when it should be switched off, so it has safely locked itself out to prevent any issues.
Your boiler has switched itself off because the internal water temperature has become too hot, usually caused by a lack of water flow through the system.
Your boiler has failed to light several times and has shut down for safety, meaning you currently have no heating or hot water.
Monthly cover means no unexpected bills when your boiler breaks down.
Affiliate links. We may earn a commission at no extra cost to you.
BoilerFaultCodes