23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is attempting to start its flame but is failing to do so, meaning you currently have no heating or hot water.
Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Your boiler has stopped working for safety reasons and requires a professional to identify the internal issue causing the system to shut down.
Your boiler has detected that there is not enough water circulating inside it to work safely, so it has shut down to prevent damage.
Your boiler has detected an issue with the internal ventilation system that prevents it from starting safely.
Your boiler's internal temperature sensor for the heating system is malfunctioning, so the boiler has shut down to prevent overheating.
Your boiler is struggling to detect the temperature outside, which may cause it to run inefficiently or stop your heating from adjusting correctly.
Your boiler has detected a faulty sensor that monitors the temperature of the exhaust fumes, meaning the system has shut down to ensure it is operating safely.
Your boiler has detected that the temperature of the exhaust gases leaving your home is too high, causing it to shut down for safety.
Your boiler is failing to light the flame or keep it running, which means it cannot provide heating or hot water safely.
Your boiler has detected that hot water isn't moving around your system properly, causing it to shut down to prevent overheating.
Your boiler has encountered a general safety error and has shut itself down to prevent damage, requiring you to attempt a reset before calling for professional help.
Safety lock-out (after four ignition attempts)
Your boiler has failed to light the flame and has turned itself off for safety reasons, meaning you currently have no heating or hot water.
Your boiler has detected that it has become dangerously hot and has automatically shut down to prevent damage or overheating.
Your boiler has detected a general internal fault that has caused it to shut down for safety reasons.
Your boiler has detected that water is not flowing properly around your heating system, usually because the pressure is too low or a pump has stopped working.
Your boiler is unable to safely clear exhaust gases because the internal fan mechanism is not responding correctly.
Your boiler's central heating sensor is not sending the correct information to the control panel, causing the heating system to stop working as a precaution.
Your boiler has lost the ability to read the outside temperature, meaning it cannot automatically adjust your heating performance based on the weather.
Your boiler has detected that a sensor measuring the temperature of the exhaust gases is not working correctly, which is preventing the system from running safely.
Your boiler has detected that the gases it is producing are too hot, so it has safely shut itself down to prevent any damage.
Your boiler has stopped working because it is overheating or the water is not circulating properly.
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BoilerFaultCodes