15 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has lost the connection to the weather sensor outside your home, meaning it cannot automatically adjust your heating based on the outdoor temperature.
Your boiler is struggling to detect the movement of water inside the system, which is preventing it from heating your home or water safely.
Your boiler is struggling to accurately measure the temperature of the water returning to it, which prevents the system from heating your home properly.
Your boiler is struggling to detect the temperature of your hot water supply, so it has safely switched off your hot water to prevent an error.
Your boiler's internal computer is struggling to communicate with its control panel or thermostat, causing it to stop operating as a safety precaution.
Your boiler has detected that the water pressure inside your heating system is either too low or too high for it to operate safely.
Your boiler has automatically shut down because its internal temperature has risen above safe operating limits.
Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage.
Your boiler has stopped working because the water pressure inside the system has risen too high, likely due to a faulty filling loop or a system issue.
Your boiler has detected that there is not enough water in the system, so it is limiting its performance to protect itself.
Your boiler has detected that a small safety wire or bridge connection inside its control panel has come loose or is missing, preventing the system from starting.
Your boiler has stopped working because the internal fan required to safely vent exhaust gases is failing to turn on.
Your boiler has failed to light its flame after several attempts and has shut down for safety.
Your boiler has stopped working because it cannot properly regulate the air flow required for safe combustion.
Your boiler has detected that the water is moving incorrectly or failing to circulate properly, which is causing it to shut down to prevent damage.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes