26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Britony Combi SE
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Your boiler is unable to start the initial flame required to heat your water or radiators.
Your boiler is struggling to stay lit because the small starter flame is too weak or unstable to safely ignite the main burner.
Your boiler is failing to keep its pilot flame lit, which means the system cannot stay fired up to provide heating or hot water.
Your boiler is struggling to keep its internal flame lit, which means the system cannot heat up and will likely shut down for safety.
Your boiler is failing to ignite the gas burner, meaning you will not have any heating or hot water until it is reset or repaired.
Your boiler is starting to heat water but quickly shuts down the flame, meaning you will likely have cold or flickering water temperatures.
Your boiler is trying to start but the burner is failing to ignite, meaning your heating and hot water will not work.
The main gas control dial on the front of your boiler has become difficult to turn or is seized, preventing you from adjusting the settings.
Your boiler has detected that the water temperature is too low for it to operate correctly, which usually means the water is not circulating properly or a sensor is faulty.
The main gas control dial on the boiler is physically stuck or difficult to turn, preventing you from operating the unit correctly.
Your boiler is not burning gas correctly, which is creating soot and could lead to dangerous carbon monoxide build-up.
Your boiler is not burning gas cleanly, which is causing a buildup of soot and potentially releasing dangerous fumes.
Your boiler has detected that the water pressure is too low for it to operate safely and effectively.
Your boiler is making a loud knocking or vibrating noise because the water isn't flowing through the main heat exchanger correctly, causing it to overheat locally.
Your boiler's internal burner is failing to switch off even when you are not using hot water or heating, which suggests a mechanical component is stuck or blocked.
Your boiler is struggling to light smoothly and is experiencing small mini-explosions or loud bangs when it tries to start.
Your boiler is making loud banging or kettling noises because of a buildup of limescale or poor water circulation, which is causing parts to overheat.
Your boiler is struggling to detect the flow of water necessary to ignite and provide you with heating or hot water.
Your boiler is struggling to heat the water properly because the internal burner is not getting enough fuel or the airflow system is incorrectly configured.
Your boiler is failing to ignite because it isn't receiving enough gas or water flow to start the heating process.
Your boiler is failing to ignite because it cannot start the small flame needed to safely light the main burner.
Your boiler's small starter flame keeps blowing out or failing to stay lit, which prevents the main boiler from igniting and providing heating or hot water.
Your boiler is struggling to keep its small starter flame lit, so it has safely shut down to prevent gas from building up.
Your boiler is struggling to breathe, causing a build-up of waste material that indicates it is not burning gas cleanly, which can be dangerous.
Your boiler is struggling to heat your hot water properly, usually because the water is flowing through it too quickly for it to warm up or because the gas supply is restricted.
Your boiler is burning gas inefficiently, which is dangerous and can lead to the production of poisonous carbon monoxide gas.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes