9 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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 is currently in standby mode and is working exactly as it should be.
Your boiler is automatically adjusting its flame intensity to save energy and balance heat, which is a normal part of its efficient operation rather than a breakdown.
Your boiler's fan is running continuously at full speed, which indicates the system has detected a safety concern and is trying to clear the air inside the unit.
Your boiler has developed an internal electrical fault, meaning the control board is likely failing and unable to safely operate the system.
Your boiler detects water movement even when it is not supposed to, which often means an internal valve is stuck or a sensor is misreading the flow.
Your boiler is struggling to push water around your radiators and taps, likely because there is trapped air in the system or the internal water pump has become faulty.
Your boiler's water pump is running constantly, which suggests the unit is stuck in a cycle trying to clear air or respond to a faulty thermostat signal.
Your boiler has stopped working because it failed to ignite, but you can attempt to restart it by pressing the red reset button.
Your boiler is struggling to light its internal flame, which means it cannot produce the heat or hot water you need.
BoilerFaultCodes