48 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected that it is running too hot and has automatically shut down to prevent damage to its internal parts.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent any damage to its internal components.
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent any damage to its internal parts.
Your boiler is struggling to move water around your heating system because the flow is blocked, restricted, or the pump is failing.
Your boiler is struggling to push water around your heating system because the flow is blocked or restricted.
Your boiler is struggling to move water around your heating system effectively, usually because there is trapped air, a blockage, or low water pressure.
Your boiler has detected that the water pressure inside the system is dangerously high, which can cause internal leaks or safety valve discharge.
Your boiler has lost the ability to measure the temperature of the water circulating through your radiators, so it has turned itself off as a precaution.
Your boiler has lost the ability to measure the temperature of the water returning to it from your radiators, so it has shut down to stay safe.
Your boiler is having trouble communicating with the outdoor weather sensor, which helps it adjust your heating based on the temperature outside.
Your boiler has detected that the external temperature safety switch, often connected to underfloor heating, has cut the connection to the system.
Your boiler is struggling to accurately monitor the temperature of the water circulating through your radiators, so it has stopped working as a safety precaution.
Your boiler has detected that water is not moving around your heating system fast enough, often due to trapped air or a closed valve.
Your boiler has detected that hot water is not flowing around your heating system properly, so it has shut down to prevent overheating.
Your boiler has detected that water is not flowing through the heating system correctly, which is preventing it from safely warming your home.
Your boiler is struggling to move water around your heating system effectively, which is causing it to stop for protection.
Your boiler is having trouble reading the temperature of the water used for your taps and shower because a sensor connection is interrupted.
Your boiler's computer has encountered a memory error, meaning it has lost its internal settings and cannot safely operate your heating or hot water.
Your boiler's internal computer is struggling to talk to its main control board, which has caused the system to stop working entirely.
Your boiler's internal computer is experiencing a communication error and has shut down to prevent potential damage to the system.
Your boiler has detected that the reset button has been pressed too many times in a short period, which has triggered a built-in safety lockout to prevent potential damage to the electronic control board.
Your boiler's central computer is experiencing a communication or internal processing fault, causing the system to shut down for safety.
Your boiler's electronic command center is experiencing a communication error and is unable to operate correctly.
Your boiler's central control computer is experiencing a communication fault, preventing it from operating safely.
Your boiler is struggling to communicate with your thermostat because of a loose connection or damaged wiring in the sensor circuit.
Your boiler is having trouble communicating with the temperature sensor for your secondary heating zone, meaning it doesn't know how warm that specific part of your home is.
Your boiler is struggling to read the temperature from an external wall controller or zone sensor, which prevents it from knowing when to turn the heating on.
Your boiler has stopped working because it cannot light the internal flame needed to heat your water.
Your boiler has detected a flame signal when it is not supposed to be running, which indicates a potential safety issue with the internal electronics or gas controls.
Your boiler is detecting that the flame is not burning correctly on the burner, which prevents it from heating your water safely.
Your boiler is struggling to light because it cannot detect a flame, which means you currently have no heating or hot water.
Your boiler has tried and failed to light the flame twice, so it has locked itself out for safety.
Your boiler has stopped because the flame inside has gone out unexpectedly while running.
Your boiler has detected that the water inside the unit is getting too hot, so it has safely shut itself down to prevent damage.
Your boiler is struggling to push air through its internal system effectively, preventing it from safely lighting the flame.
Your boiler is struggling to read the temperature for a secondary heating zone, meaning that specific part of your home may not heat up correctly.
Your boiler is having trouble communicating with the temperature sensor for your secondary heating zone, which may prevent that part of your home from heating up properly.
Your boiler is having trouble communicating with one of its internal temperature sensors, which may cause your heating or hot water to work inconsistently.
Your boiler is having trouble 'sensing' the temperature of the water returning from your radiators, which prevents it from heating your home correctly.
Your boiler is having trouble communicating with the temperature sensor for your secondary heating area, which may cause that part of the home to struggle to heat up correctly.
Your boiler is having trouble reading the water temperature for one of the specific heating zones in your home, which may cause that part of the system to stop working correctly.
Your boiler has detected that the water temperature in your secondary heating circuit is higher than it should be, causing the system to shut down to prevent damage.
Your boiler has detected that the water temperature in one part of your heating system is higher than it should be, causing it to shut down for safety.
Your boiler has disabled your heating system because it cannot detect or communicate with the controls that request heat for your radiators.
Your boiler has detected that the water pressure in your heating system is too low to operate safely, so it has shut down to protect itself.
Your boiler has detected a communication error with its internal combustion control system, meaning it cannot safely regulate the burner.
Your boiler has detected that the water pressure inside the system is too low to run safely and needs to be topped up.
Your boiler has detected an internal electronic error before trying to ignite and has safely turned itself off to prevent any risk.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes