26 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Concord CXA
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Your boiler has detected a general internal fault that requires a specialist to correctly identify and resolve.
Your boiler has stopped working because it cannot safely exhaust fumes or confirm that the internal fan is moving air correctly.
Your boiler has stopped working because it cannot confirm that the fan is safely clearing waste gases from the system.
Your boiler is currently taking a short mandatory rest to prevent unnecessary wear and tear on its internal parts.
Your boiler has reached its target temperature and is taking a short, two-minute break to prevent components from wearing out by switching on and off too frequently.
Your boiler has detected that the temperature sensor used to monitor the water inside the unit is broken or sending incorrect signals.
Your boiler has lost the ability to accurately measure its own temperature, so it has safely shut down to prevent potential overheating.
Your boiler has stopped working because it failed to light the gas flame successfully.
Your boiler's temperature sensor has stopped working correctly, meaning the system can no longer tell how hot the water is and has shut down as a precaution.
Your boiler has tried to start up several times but cannot establish a stable flame to begin heating.
Your boiler has stopped working because it cannot detect a flame, meaning it has safely shut down to prevent gas from flowing without being burned.
Your boiler has stopped working because the internal fan that safely removes exhaust gases is not running correctly.
Your boiler has encountered an internal timing error or electrical communication fault because it didn't enter the correct setup mode when its gas control valves were being linked.
Your boiler has detected that the water levels inside the system are incorrect, or the sensor that monitors the water level is faulty.
Your boiler is unable to safely control the flow of gas needed to stay alight, so it has shut down to prevent any risks.
Your boiler is unable to light because the internal system that controls the gas flow has stopped working correctly.
Your boiler has unsuccessfully tried to start five times and has now shut itself down for safety reasons to prevent a gas buildup.
Your boiler is not starting because it cannot detect water moving through the system to prevent overheating.
Your boiler's outdoor temperature sensor is not communicating correctly, which may affect how efficiently the system adjusts your heating based on the weather.
Your boiler has lost the connection to the weather sensor that tells it how cold it is outside, so it may not heat your home as efficiently as usual.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler has become too hot and has automatically shut down to prevent damage to the internal components.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler has stopped heating up because the water is not being pushed through the pipes as it should be.
Your boiler has stopped heating up because the water is not being circulated through the system correctly.
Your boiler is currently switched off or in sleep mode and needs to be manually turned back on.
BoilerFaultCodes