26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is having trouble directing water properly between your radiators and your taps, which usually means it is stuck providing only heating or only hot water.
Your boiler has detected a generic internal system error that prevents it from operating normally, and it requires a professional to diagnose the specific underlying cause.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Your boiler is failing to stay lit, which means it has safely shut itself down because it cannot consistently produce or hold a flame.
Your boiler has detected an issue with the fan that safely clears exhaust gases, preventing it from starting up for your safety.
Your boiler has lost connection to the weather sensor outside your home, though your heating and hot water will usually still work normally using the boiler's internal settings.
Your boiler has detected that the electrical supply coming into your home is too low for it to operate safely.
Your boiler has detected a communication error with its internal computer or a wiring fault near the gas supply, meaning it has safely switched off to prevent potential issues.
Your boiler has detected a software or configuration error in its internal computer, which has caused it to shut down for safety reasons.
Your boiler's main control board is stuck in a special programming mode rather than operating normally to heat your home.
Your boiler's internal computer has suffered a critical failure and can no longer control the heating system, meaning the unit will not operate.
Your boiler's main control computer is experiencing a critical error and is unable to communicate properly, meaning your heating and hot water will not work.
Your boiler has detected that the temperature sensors for the water going in and out are reporting incorrect or swapped readings, which has caused the system to shut down for safety.
Your boiler has detected a dangerous difference in temperature between its internal sensors and has automatically shut down to prevent overheating.
Your boiler has detected a persistent internal fault and has automatically shut down for safety reasons.
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 tried to start up several times but failed to ignite the gas burner.
Your boiler's temperature-sensing component is malfunctioning, which prevents it from safely controlling the heat, so it has turned itself off to prevent overheating.
Your boiler has detected an issue with the sensor that monitors the temperature of the water returning to the unit, causing it to stop running for safety.
Your boiler thinks a flame is burning even though it shouldn't be, causing the system to shut down for safety.
Your boiler has temporarily locked itself out for safety after too many failed attempts to start up.
Your boiler's main control board has accidentally entered its factory setup mode rather than running normally to heat your home.
Your boiler is having trouble directing water correctly between your radiators and your taps, which usually means the internal valve mechanism is stuck or struggling.
Your boiler is simply showing a status message rather than a fault, which appears right after displaying its recent error history.
Your boiler is having trouble directing water between your heating system and your taps because a motorised valve isn't moving correctly.
Your boiler's main control board has accidentally entered its programming setup mode rather than running normally.
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BoilerFaultCodes