15 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has lost communication with the weather sensor outside your home and is now running on its default safety settings.
Your boiler is struggling to detect the flow of water through its system, which means it cannot safely heat your home or provide hot water.
Your boiler is struggling to accurately read the temperature of the water returning to it, which prevents it from heating your home reliably.
Your boiler is having trouble detecting the temperature of the water coming from your taps, which means it cannot heat your hot water properly.
Your boiler is having trouble communicating internally with its control components, meaning it cannot currently receive instructions to heat your home.
Your boiler is currently running a brief internal safety check to clear out trapped air after the electricity was recently interrupted or switched back on.
Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage.
Your boiler has switched itself off because it has become too hot internally, likely due to a lack of water flow or a blockage.
Your boiler has lost its internal electrical connection signal, which is usually caused by low water pressure or a loose wiring link inside the unit.
Your boiler's internal fan is failing to start, which means the system cannot safely clear exhaust fumes and has shut down as a precaution.
Your boiler has tried to light several times but cannot establish a flame, meaning your heating and hot water will not work.
Your boiler's internal fan, which is responsible for safely venting fumes, is failing to spin at the correct speed, causing the system to stop working for safety reasons.
Your boiler has detected an abnormal temperature difference between the water leaving it and the water returning, which usually indicates a circulation problem inside the system.
This is not an error code, but merely a notification confirming that the boiler's manual testing mode has finished successfully.
This code is not an error; it simply confirms that your boiler has finished its setup or testing mode and is returning to normal operation.
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BoilerFaultCodes