21 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is having trouble reading the outdoor temperature properly, so it is temporarily using a safe fallback setting to keep your heating running.
Your boiler has temporarily stopped working because it cannot properly read the water pressure inside the system due to a faulty sensor or loose wiring connection.
Your boiler is not receiving the correct outdoor temperature reading, though your heating and hot water will usually continue to run using a backup setting.
Your boiler has detected an electrical fault with an internal temperature monitor, meaning it cannot accurately read how hot the water is and has safely shut down.
Your boiler has temporarily stopped working because it has lost connection to a key internal temperature monitor.
Your boiler has detected an electrical fault with an internal sensor, causing it to shut down for safety reasons so it cannot provide heating or hot water.
Your boiler has lost the connection to a sensor responsible for monitoring the heat, so it has safely shut itself down to prevent overheating.
Your boiler has stopped working because it cannot confirm that the internal flame is burning correctly, so it has shut down for your safety.
Your boiler has detected an issue with the internal valve that controls the gas supply, meaning it cannot safely start up to provide heating or hot water.
Your boiler is temporarily locking out because it has detected an issue with the gas control valve responding correctly.
Your boiler has stopped because the flame went out unexpectedly, which usually happens if the gas supply is interrupted or a safety sensor fails to detect the flame.
Your boiler's internal computer has identified an incorrect configuration card, which prevents it from operating safely.
Your boiler is failing to ignite because it cannot maintain a stable flame at the lowest power setting.
Your boiler is trying to ignite but cannot detect a flame, so it has safely shut down to prevent gas from building up.
Your boiler has detected invalid temperature readings, meaning it cannot safely determine how much to heat your water and has switched itself off to prevent potential damage.
Your boiler has shut down because water is not flowing through it properly, which usually means the system needs topping up with water or a valve is closed.
Your boiler has temporarily stopped working because water is not flowing through the system properly or the pressure is too low.
Your boiler has detected that the water inside is heating up far too quickly, usually because water is not flowing properly through the system.
Your boiler has detected that the water isn't flowing properly or the internal temperature sensors disagree, which causes it to shut down to prevent overheating.
Your boiler has detected that the water pressure in your heating system is dropping much faster than it should, which usually points to a leak somewhere in your radiators, pipes, or the boiler itself.
Your boiler has temporarily stopped working because the water pressure inside the heating system has dropped too low.
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BoilerFaultCodes