31 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Concord CXD
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Your boiler has detected an internal fault that prevents it from operating safely or correctly.
Your boiler is failing to detect that it has enough airflow to safely light the flame, so it has shut itself down to prevent a potentially hazardous situation.
Your boiler is working normally and the light simply indicates it is switched on and firing.
Your boiler has detected an issue with its internal sensors and has stopped running to prevent any damage or incorrect temperature readings.
Your boiler has lost the ability to monitor its own temperature, so it has safely shut itself down to prevent overheating.
Your boiler has stopped working because it failed to light the flame, so it has purposefully shut itself down for safety.
Your boiler is operating normally and is currently firing to provide heat.
Your boiler has lost its ability to accurately measure the temperature of the water being heated for your radiators, causing it to stop running as a safety precaution.
Your boiler is failing to start because it cannot successfully ignite the gas after several attempts.
Your boiler has stopped working because it cannot light the internal flame safely, so it has locked itself to prevent gas from flowing.
Your boiler has detected that gases are not being cleared away properly through the flue, which is a safety mechanism to prevent harmful fumes from entering your home.
Your boiler has stopped working because the internal component responsible for pushing stale air and gases out of the flue is not functioning correctly.
Your boiler's internal air system is failing to move waste gases out of the flue, which is preventing the unit from firing up safely.
Your boiler has detected that a internal safety sensor is not reading correctly, which prevents it from safely heating your home.
Your boiler has detected that a safety device designed to prevent water overflow or blockages has been triggered, causing the system to shut down.
Your boiler is unable to safely control the flow of gas needed to stay alight, so it has shut down as a safety precaution.
Your boiler is unable to safely control the flow of gas needed to stay lit, so it has shut down to avoid a potential hazard.
Your boiler has tried to fire up five times without success and has shut itself down for safety.
Your boiler has stopped working because it failed to ignite the gas burner after five repeated attempts.
Your boiler has failed to start up or stay burning, so it has purposefully turned itself off for safety and will not heat your home or water until fixed.
Your boiler has stopped heating because it cannot detect any water moving through the system to keep it safe.
Your boiler is struggling because it has lost the signal from the temperature sensor installed on the outside of your property, which tells it how hard to work based on the weather.
Your boiler has lost connection with its outdoor thermometer, meaning it might struggle to adjust its temperature correctly for the weather.
Your boiler is struggling because it has lost the signal from the weather sensor installed outside your home, meaning it cannot automatically adjust your heating based on the temperature outdoors.
Your boiler has shut itself down as a safety precaution because the water inside has become far too hot.
Your boiler has switched itself off because it became too hot, acting as a safety precaution to prevent damage.
Your boiler has become too hot and has automatically shut down to prevent damage or safety issues.
Your boiler has detected that water is failing to circulate correctly through the system, which will prevent it from heating your home or providing hot water.
Your boiler is unable to move hot water around the system, meaning your heating and hot water will not work.
Your boiler is unable to create the spark needed to light the gas burner, meaning the system cannot fire up to provide heat.
Your boiler is currently switched off and waiting for you to turn it back on.
BoilerFaultCodes