15 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected that the core part responsible for heating your water is failing to transfer heat properly, causing the system to shut down for safety.
Your boiler is struggling to clear exhaust gases properly, likely because the ventilation system is blocked or the internal sensor is misreading the airflow.
Your boiler's internal air extraction system is failing, which prevents it from safely igniting and providing heating or hot water.
Your boiler is struggling to clear exhaust fumes safely, so it has turned itself off to prevent any risk.
Your boiler's air pressure sensor is detecting an issue with the airflow system which is stopping the boiler from igniting correctly.
Your boiler is struggling to push out waste gases properly, causing it to lock itself down for safety.
Your boiler is struggling to clear exhaust gases properly, which means it has automatically shut down to keep your home safe.
Your boiler has detected that the air supply or exhaust system is not working correctly, meaning it has safely shut down to prevent unsafe gases from building up.
Your boiler is struggling to detect that the water flow has been turned on, which prevents it from firing up to heat your home or provide hot water.
Your boiler is struggling to detect water flowing through the system properly, which is stopping your heating and hot water from working.
Your boiler has lost its connection to the power supply or the main control board has experienced a temporary communication error.
Your boiler has failed to ignite, which means it cannot provide any heating or hot water until the flame is established.
Your boiler's pilot light is going out as soon as you let go of the control knob, meaning the burner cannot stay lit to provide heat.
Your boiler has detected an issue preventing it from keeping the flame lit, so it has safely shut itself down.
Your boiler has stopped working because it couldn't safely ignite its internal flame, so it has shut itself down to keep your home safe.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes