26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is currently showing a status indicator that typically requires an engineer to check the system setup or internal settings.
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 is having trouble reading the outdoor temperature, which it uses to help run your heating more efficiently.
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 has lost its memory settings and needs to be re-programmed to match your specific model.
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 temporarily stopped working because it tried to start up five times without successfully lighting.
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 stopped working because it failed to light successfully five times in a short space of time.
Your boiler has accidentally entered its factory setup mode, meaning the control board needs to be properly reconfigured.
Your boiler is displaying a general system status or operational mode indicator rather than a specific fault.
Your boiler is currently running a safety check or operating normally, but if this code stays on and your heating stops working, it simply means the system needs a reset.
Your boiler is currently showing a status indicator that typically requires an engineer to check the internal settings or wiring.
Your boiler's main control system has accidentally entered a software programming mode instead of normal operation.
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BoilerFaultCodes