49 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Megaflo System / Baxi Platinum Combi
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Your boiler’s internal computer has encountered a critical communication error and cannot operate safely.
Your boiler’s internal computer has encountered a critical communication error and cannot operate safely.
Your boiler has detected a safety concern or internal failure and has shut itself down to prevent damage.
Your boiler has failed to ignite, meaning it cannot create the flame needed to provide you with heating or hot water.
Your boiler is struggling to circulate water properly or is heating up too quickly, causing it to shut down for safety.
Your boiler has switched itself off because it has become too hot internally, likely due to a lack of water or a blockage preventing water from moving around the system.
Your boiler has shut down because it has either gotten too hot or it is unable to supply gas to the burner.
Your boiler's electronic brain has detected an internal safety error and has shut down for protection.
Your boiler has detected an issue with how the fuel is burning or how the main heat exchanger is performing, causing it to shut down for safety.
Your boiler's main internal computer has developed a serious communication fault and can no longer control the heating process safely.
Your boiler has stopped working because the water pressure in the central heating system is too low or a sensor has failed.
Your boiler has stopped working because the internal computer and its sensors are no longer communicating correctly with each other.
Your boiler is sensing a flame even after it has tried to turn the gas off, which is a safety conflict that requires a professional inspection.
Your boiler is detecting a flame at the wrong time, suggesting that gas might be leaking into the burner when it should be shut off.
Your boiler has stopped working because the internal fan, which safely pushes exhaust gases out of the flue, is not spinning at the correct speed.
Your boiler is struggling to move water through the system properly, which is causing it to shut down to prevent overheating.
Your boiler has stopped working because water is not circulating through the system properly, often due to a pump issue or a closed valve.
Your boiler has tried to light several times but has failed to create a flame, causing the system to shut down for safety.
Your boiler has shut down because it is unable to safely discharge exhaust fumes or has detected that the flue system is overheating.
Your boiler has shut itself down for safety because it tried to light several times but couldn't maintain a steady flame.
Your boiler has detected an electrical fault with the sensor that monitors water flow, meaning it cannot safely determine if water is moving through the system.
Your boiler is unable to read the hot water temperature correctly, meaning you likely have no hot water or unstable water temperatures.
Your boiler has detected a fault with the temperature sensor for your hot water, which means it cannot safely heat the water for your taps.
Your boiler’s internal computer has encountered a critical communication error and cannot operate safely.
Your boiler's computer has detected a serious internal fault that prevents it from operating safely and reliably.
Your boiler thinks a flame is present even though it hasn't turned the gas on, usually caused by a blocked drain or a faulty sensor.
Your boiler has detected that its electrical wires are connected the wrong way round at the power source, preventing it from starting up safely.
Your boiler is detecting an issue with the quality or frequency of the electricity coming from your mains supply, causing the system to shut down for safety.
Your boiler has detected an internal electrical connection problem that is preventing it from monitoring the system pressure correctly.
Your boiler has detected that a temperature sensor responsible for monitoring water returning to the unit has disconnected or broken, preventing it from running safely.
Your boiler has stopped working because one of its internal temperature sensors has developed an electrical fault and can no longer send information to the main control board.
Your boiler's computer brain has encountered a serious internal error and can no longer control the heating or hot water safely.
Your boiler has stopped working because the water pressure in the system is too low.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler has noticed that the water pressure is getting a bit low and needs a small top-up to keep running efficiently.
Your boiler has reached a critically high water pressure that is unsafe for continued operation.
Your boiler has detected that the water pressure inside the system is dangerously high while it is running, which can put unnecessary stress on your pipework and internal components.
Your boiler has switched itself off because the water pressure is too low for it to run safely.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has lost water pressure and has shut itself down to prevent damage to the internal components.
Your boiler has detected that there is not enough water pressure in the central heating system to operate safely.
Your boiler has stopped working because the water pressure inside your heating system has dropped too low.
Your boiler has detected that the water pressure is too low, which prevents the system from running safely and efficiently.
Your boiler has shut down because there is too much water pressure in the central heating system.
Your boiler has automatically shut down because the water pressure inside your heating system has become dangerously high.
Your boiler has shut down because there is too much water pressure in the system, which could lead to leaks if not addressed.
Your boiler has shut down completely for safety reasons and will not provide heating or hot water until it is manually reset or repaired.
Your boiler has stopped working because it failed to light the flame, so it has purposefully shut itself down for safety.
Your boiler has automatically turned itself off because the water pressure inside the heating system has fallen too low to operate safely.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes