22 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has temporarily paused because the water inside has become slightly hotter than it is supposed to be.
Your boiler has temporarily stopped working because a safety switch or external device connected to it, such as a room thermostat or timer, has broken the circuit.
Your boiler has temporarily paused heating because the radiators have already reached the requested temperature, but the thermostat is still asking for heat.
Your boiler has temporarily stopped because it detected that the water inside is getting hotter than the temperature you have set, likely due to poor circulation.
Your boiler has switched itself off because the water inside is heating up too quickly or too unevenly, which often happens when water cannot circulate through your radiators properly.
Your boiler is perfectly healthy and is simply resting in its normal standby state, waiting for a signal to provide heating or hot water.
Your boiler is trying to start up, but it cannot successfully light the internal flame after several attempts, so it has shut down for safety.
Your boiler is currently performing a necessary safety check before it attempts to ignite, but it has stalled at this initial stage.
Your boiler is failing to light the flame, which means it cannot produce any heating or hot water for your home.
Your boiler is currently working correctly and is simply letting you know it is busy heating your radiators.
Your boiler has failed to light the flame after several attempts and has switched itself off to prevent a build-up of unburnt gas.
Your boiler is currently in a temporary cooling-down period and will restart automatically once it reaches the required temperature.
Your boiler is continuing to circulate water even though it should have finished, which suggests the system is struggling to reset after heating your home or water.
Your boiler has detected that the water pressure inside the system is far too low to function safely.
Your boiler has detected that the internal fan responsible for venting exhaust gases safely is either not spinning or communicating properly, so it has shut down to keep your home safe.
Your boiler has temporarily stopped working and needs to be manually restarted using the reset button.
Your boiler has detected that the internal casing is getting too hot, indicating it is struggling to ventilate correctly or is running too hot internally.
Your boiler has experienced a temporary glitch that has safely shut it down and simply needs to be manually restarted using the reset button.
Your boiler has detected that some of its internal settings have drifted outside of their safe operating limits, and it has stopped working as a precaution.
Your boiler has detected an internal software or settings error, which is preventing the system from starting up safely.
Your boiler has lost its programmed settings and needs to be reconfigured by a professional to operate correctly.
Your boiler's external temperature sensor and frost protection thermostat are sending conflicting signals to your heating controller.
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BoilerFaultCodes