9 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Logic Combi
Pick the one you have. The fault codes, GC numbers and manual differ by type.
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 communication problem or a fault with the sensor that controls your central heating temperature.
Your boiler has detected a fault with the temperature sensor that controls your hot water, meaning it cannot accurately measure how hot the water is.
Your boiler has stopped working because the internal fan, which safely helps the system breathe, is not spinning.
Your boiler is receiving power but cannot ignite because it isn't detecting the correct gas pressure required to start the burner.
Your boiler is trying to start up but is failing to create the spark or flame needed to heat your water.
Your boiler is struggling to light or keep a flame burning correctly because the gas and air mixture isn't balanced.
Your boiler is failing to ignite or stay lit, meaning you will not have any heating or hot water until the issue is resolved.
Your boiler has stopped working because the water level inside the system has dropped too low and needs topping up.
Your boiler has lost power because an internal fuse has blown, likely caused by an electrical fault in the pump.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes