22 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Suprima HE
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
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Your boiler has detected a fault and has safely shut itself down to prevent damage, meaning you currently have no heating or hot water.
Your boiler has stopped working because it can no longer accurately read the temperature of the water inside it.
Your boiler has detected that it is getting too hot and has safely shut itself down to prevent damage.
Your boiler has detected that it is dangerously overheating and has automatically shut down to prevent damage or a safety hazard.
Your boiler is trying to start up but is unable to ignite its flame, so it has safely shut down to prevent gas from building up.
Your boiler has detected that the flame inside has gone out unexpectedly while it was running, so it has safely shut itself down to prevent gas from escaping.
Your boiler is failing to detect the airflow needed for safe operation, so it has shut down to prevent it from firing up improperly.
Your boiler has detected a faulty connection to a safety sensor responsible for monitoring the outer casing, which will prevent the heating and hot water from turning on.
Your boiler has detected that the internal temperature is too high and has shut itself down to prevent damage or safety risks.
Your boiler's main brain has stopped working correctly, meaning the system cannot communicate or operate safely to heat your home.
Your boiler has lost all power and is completely switched off, meaning you currently have no heating or hot water.
Your boiler has detected that it is running without enough water inside, meaning it cannot safely heat your home.
Your boiler has lost the ability to detect if there is enough water inside, so it has safely shut down to prevent damage.
Your boiler is struggling to ensure the air required for the heating process is moving correctly, so it has safely shut itself down to prevent any risk.
Your boiler is attempting to light but is failing to stay on, meaning it cannot provide you with any heating or hot water.
Your boiler is struggling because a small internal sensor that tracks water movement has been dislodged or is not seated correctly.
Your boiler has detected a safety fault and has stopped working to prevent further issues, meaning you currently have no heating or hot water.
Your boiler is currently unable to read the temperature of the water returning to it, so it has shut down as a precaution to prevent overheating or inefficient use.
Your boiler's temperature sensor is providing incorrect information, causing the system to stop operating correctly to ensure safety.
Your boiler has detected an electrical fault in the system that tells it when a flame is present, causing it to shut down for safety reasons.
Your central heating system has trapped air inside, causing the pump to struggle and making the boiler shut down as a precaution.
Your boiler has detected an electrical connection error where live electricity is reaching a part of the system that should be neutral, which is a significant safety concern.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes