23 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Baxi 200 Combi
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The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.
| GC number | Appliance (register name) | Produced |
|---|---|---|
| 47-077-25 | 124 COMBI | 2016–present |
| 47-077-26 | 128 COMBI | 2016–present |
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Your boiler has lost communication with the gas control unit, meaning it cannot ignite safely to provide heating or hot water.
Your boiler is unable to control the flow of gas into the system, which means it will shut down for safety purposes.
Your boiler has lost its ability to accurately measure the temperature of the water used for your radiators, causing the system to shut down for safety.
Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.
Your boiler has detected a problem with the sensor that monitors the temperature of the water returning from your radiators.
Your boiler has lost its internal settings and needs a professional to recalibrate the software so it can safely control the combustion process.
Your boiler has detected that water isn't moving through the system properly, which is causing it to shut down to prevent overheating.
Your boiler has overheated because the water isn't moving through the system properly, causing it to shut down for safety.
Your boiler has switched off because there is too much water pressure in the system, which can put unnecessary strain on the internal seals and components.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler has detected that water is not moving around the system correctly, causing it to overheat and shut down for safety.
Your boiler has lost its flame while it was running, which means it cannot continue to provide heat or hot water.
Your boiler has shut down because it detected that the exhaust gases are getting too hot, which is a safety feature to prevent damage or dangerous fumes.
Your boiler has tried to light several times but has failed to sense a flame, meaning your heating and hot water will not work.
Your boiler is attempting to ignite but cannot detect a flame, meaning it has locked itself out for safety.
Your boiler has lost its connection to the gas supply or cannot detect the gas it needs to ignite, which has caused it to shut down for safety.
Your boiler has detected an issue with the fan that safely removes exhaust gases, meaning the system has shut down as a safety precaution.
Your boiler is overheating too quickly because water isn't moving through the system properly, causing it to shut down to prevent damage.
Your boiler is struggling to accurately measure the temperature of your hot water, which usually means the water will either be too cold or not come on at all.
Your boiler thinks it sees a flame when there shouldn't be one, which stops it from starting up correctly for safety reasons.
Your boiler has stopped working because the water pressure inside the system has dropped too low.
Your boiler's flame has gone out because air has entered the gas pipes or the gas supply is not steady enough to keep it running.
Your boiler is struggling to light because there is either a blockage in the gas supply or air trapped in the pipes, often caused by a recent gas interruption or frozen pipes.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes