51 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Baxi Duo-tec Combi
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 problem with its internal temperature sensors, which means it cannot accurately tell how hot the water is and has stopped working for safety.
Your boiler is failing to clear its system of air before starting, so it has safely shut down to prevent ignition.
Your boiler is failing to light the fuel inside even though it is trying to start, so it has safely shut itself down to prevent a gas build-up.
Your boiler's internal computer has crashed or is struggling to process the reset command, preventing it from starting up again safely.
Your boiler is lighting up but shutting off shortly after because it cannot confirm that the flame is staying on, meaning you currently have no heating or hot water.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Your boiler is struggling to light or keep its flame burning, which has caused it to shut down for safety.
Your boiler has sensed that it is becoming too hot and has automatically shut down for safety purposes.
Your boiler has detected that water is not circulating correctly through the system, which prevents it from heating up safely.
Your boiler has detected an issue with the air flow or the internal fan, which means it cannot safely exhaust fumes and has stopped working as a precaution.
Your boiler is currently preheating the internal water to ensure you get hot water quickly when you turn on a tap.
Your boiler is struggling to detect the temperature of the water coming from your taps, which means it cannot reliably provide hot water.
Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Your boiler is struggling to clear exhaust gases safely, so it has stopped working to prevent any potential build-up of fumes.
Your boiler is struggling to circulate water properly, likely because the pressure inside your heating system has dropped too low or the internal pump is stuck.
Your boiler is struggling to detect the temperature of the water for your taps, which means it cannot reliably provide hot water.
Your boiler has lost its ability to measure the temperature of the water being sent to your radiators, so it has shut down as a precaution to prevent overheating.
Your boiler is struggling to accurately measure the temperature of the water coming out of your taps, which may cause your hot water to fluctuate or stop working entirely.
Your boiler is struggling to monitor the temperature of the water used for your radiators, causing the system to stop running as a safety precaution.
Your boiler is failing to detect that the fan is pushing burnt gases safely out of the flue, so it has shut down to prevent unsafe operation.
Your boiler is operating normally and the flame is lit to provide you with heating or hot water.
Your boiler is not firing up because it isn't receiving the necessary signal or fuel to start the heating process.
Your boiler has detected a generic internal problem within the central heating system that is preventing your radiators from warming up.
Your boiler is failing to detect when you turn on your hot water tap, meaning you have heating but no hot water.
Your boiler thinks a hot water tap is turned on even when it isn't, which is preventing the system from working correctly.
Your boiler is failing to detect when the hot water is turned on, meaning the system won't fire up to heat the water for your taps.
Your boiler has detected that there is not enough water inside the system to operate safely, causing it to shut down to prevent overheating.
Your boiler has detected an issue with the internal fan that clears waste gases, meaning the system has safely shut down to prevent any hazards.
Your boiler has detected that it has become too hot and has automatically shut down to prevent damage, causing it to stop heating your home and water.
Your boiler has detected that the fan, which safely removes waste gases from your home, has stopped spinning or is struggling to start.
Your boiler has tried to ignite but was unable to stay lit, meaning your heating and hot water will not work until it is reset or repaired.
Your boiler is trying to start but the flame is not catching, meaning you currently have no heating or hot water.
Your boiler has detected a problem with the temperature sensor that monitors the water leaving the unit, meaning it cannot safely regulate heat.
Your boiler is failing to light the gas flame despite several attempts, meaning you will not have any heating or hot water until the system is reset.
Your boiler has detected that its electrical power supply wires have been connected in the wrong order, which is a significant safety risk.
Your boiler has stopped working because it cannot light its burner or has safely shut down to prevent overheating.
Your boiler is not receiving enough electricity from the mains supply to operate safely and has shut down as a precaution.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler is receiving electrical power, which simply confirms that it is turned on and ready to operate normally.
Your boiler has stopped working because the water pressure inside your heating system has dropped too low.
Your boiler has too much water inside, causing the pressure to rise to a level where the safety system is forced to drain it out.
Your boiler has lost water pressure, which prevents it from firing up to provide heating or hot water.
Your boiler has become dangerously pressurized, which is causing it to automatically release water to prevent a potential rupture.
Your boiler's water pump is failing to start, which prevents heat from moving around your home and keeps the boiler from working correctly.
Your boiler has attempted to light the gas burner multiple times but has failed to detect a flame, causing it to shut down for safety reasons.
Your boiler has detected an internal error and has entered a lock-out state, meaning it has switched itself off to prevent damage.
Your boiler has detected an issue with the sensor that monitors the temperature of the water returning from your radiators.
Your boiler has detected that it got too hot and has automatically switched itself off to stay safe.
Your boiler is simply indicating that it has detected a demand for hot water and is operating normally in hot water mode.
Your boiler is simply indicating that it is currently operating to provide heat for your radiators.
Your boiler is receiving electrical power and is currently in standby mode or ready to operate.
BoilerFaultCodes