15 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is failing to keep its small pilot flame lit, which prevents the main burner from igniting and stops your heating and hot water from working.
Your boiler's air-moving fan is struggling or rattling, which could lead to your heating or hot water cutting out.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler is failing to ignite properly because debris or trapped air is interfering with the gas or water flow, meaning your heating and hot water will not work.
Your boiler is struggling to light smoothly, causing a small 'pop' or bang sound when it tries to start instead of igniting quietly.
The dial you use to turn your boiler on or off has become extremely difficult to move, which likely means the internal lubricant has dried out or the knob was not put back on correctly after previous work.
Your boiler is making loud banging or kettling noises because of internal debris buildup, incorrect gas settings, or restricted water circulation.
Your boiler is struggling to detect enough water flowing through it to safely turn on your hot water taps.
Your boiler is not heating the water effectively because it is having trouble regulating the flow of gas or detecting the water movement required to trigger the heating process.
Your boiler is failing to ignite the flame needed to heat your water or home, meaning you currently have no heating or hot water.
Your boiler is failing to ignite because it cannot start the small pilot flame required to trigger the main burner.
Your boiler is failing to keep its small starter flame lit, which prevents the main system from firing up to provide you with heating or hot water.
The small pilot flame that acts as a signal to ignite your boiler is too weak or flickering, so the system is shutting down for safety to prevent gas from escaping unburnt.
Your boiler is struggling to keep a steady flame, which suggests either moisture is trapped in the gas supply or the system cannot breathe properly through its exhaust.
Your boiler is not burning fuel cleanly, which can create dangerous gases, so you should stop using it immediately.
BoilerFaultCodes