94 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler has detected an internal issue where the fan is not spinning at the required speed to safely exhaust gases.
Your boiler has failed to ignite because it was unable to sense a flame after starting up.
Your boiler has detected a failure to ignite the flame, meaning it is currently unable to provide heating or hot water.
Your boiler has detected that it is not receiving enough water flow to operate safely and has shut itself down to prevent damage.
Your boiler has detected that the flame inside has unexpectedly gone out, so it has safely shut down to stop any unburned gas from building up.
Your boiler has detected that it is overheating and has shut itself down to prevent any damage to the internal parts.
Your boiler has temporarily shut down because an internal safety switch detected that the water inside has gotten too hot.
Your boiler has failed to detect a flame, meaning it cannot ignite to provide you with heating or hot water.
Your boiler has detected an issue with the water pressure sensor, which is preventing it from operating correctly.
Your boiler has detected an issue with the airflow management system, meaning it cannot operate safely and has shut itself down to prevent damage.
Your boiler has detected an issue with the air supply or exhaust system, meaning it cannot safely vent the gases produced during combustion.
Your boiler has detected an issue with the air pressure inside the unit, meaning it cannot safely vent the exhaust gases.
Your boiler is failing to light the flame properly, which means it cannot produce heating or hot water until the ignition system is checked.
Your boiler is struggling to breathe properly because the pipework that lets air in and smoke out is likely blocked, frozen, or damaged.
Your boiler has detected an issue with the air intake or exhaust system, meaning it cannot safely vent gases and has shut down to protect your home.
Your boiler has detected an issue with the water flow or pressure sensor, meaning it cannot accurately tell if water is moving through the system to heat it safely.
Your boiler has detected an issue with the air supply or exhaust system, which prevents it from operating safely.
Your boiler is failing to detect the necessary internal pressure or airflow, causing the system to lock out for safety.
Your boiler has detected an issue with the flame and has safely shut itself down to prevent any unsafe operation.
Your boiler has detected an issue with the sensor used to monitor the water pump, preventing the system from circulating water correctly.
Your boiler has detected a problem with the internal flow sensor, which means it cannot accurately measure the movement of water to heat your home.
Your boiler has detected an internal communication error with its main control unit, causing it to shut down for safety.
Your boiler has detected an internal communication failure between its main control boards, which prevents it from operating safely.
Your boiler has detected an issue with the internal air or exhaust system that prevents it from firing up safely.
Your boiler has detected an internal communication error between its main control boards, which prevents it from operating correctly.
Your boiler is struggling to communicate with its internal control system, which has caused it to shut down for safety reasons.
Your boiler has lost communication with the internal 3-way valve, meaning it cannot correctly switch between heating your radiators and providing hot water.
Your boiler's main control panel is having trouble talking to the internal computer, which has caused the system to stop working.
Your boiler has detected that its internal water temperature has become dangerously high and has shut itself down to prevent damage.
Your boiler is failing to light the flame needed to produce heat and hot water.
Your boiler is detecting a flame inside the unit even when it has been told to turn off, which triggers a safety shutdown to prevent gas build-up.
Your boiler is failing to light the internal flame needed to produce heat and hot water safely.
Your boiler has detected that it is getting dangerously hot and has shut itself down to prevent damage or fire risk.
Your boiler is detecting an issue with water flow or heat levels, which could mean dangerous air or gas is trapped inside where it shouldn't be.
Your boiler is struggling to read its internal temperature correctly, which is preventing it from safely heating your home's water.
Your boiler is struggling to accurately measure its internal water temperature, so it has stopped working as a safety precaution.
Your boiler has temporarily stopped working because it has detected an issue with the temperature sensor on its exhaust flue.
Your boiler has detected an electrical fault with the temperature sensor on the exhaust flue, causing it to shut down for safety.
Your boiler is having trouble controlling the air and gas balance required for safe combustion, so it has safely shut itself down to prevent any issues.
Your boiler has detected an issue with its internal airflow and safety sensors, which temporarily stops it from operating to keep your home safe.
Your boiler has detected an issue with the internal air flow safety switch, which stops the boiler from operating if it is stuck in the closed position.
Your boiler has detected an issue with the internal airflow safety switch, which stops the boiler from running to ensure dangerous gases cannot build up.
Your boiler has stopped working because the internal fan which clears waste gases isn't spinning, meaning it has safely shut down to prevent any risk.
Your boiler has detected an issue with the internal fan that safely clears combustion gases, so it has locked out to keep your home safe.
Your boiler is struggling to breathe because it cannot effectively move air through the system, meaning it has shut down for safety.
Your boiler has detected a blockage in the exhaust flue or a problem with the internal fan, which stops it from safely clearing waste gases outside.
Your boiler has temporarily stopped working because it has detected a blockage in the exhaust flue that removes waste gases outside.
Your boiler has detected a blockage in the exhaust flue that removes waste gases outside, so it has safely shut down to prevent harmful fumes from building up in your home.
Your boiler's air pressure sensor is failing to detect the correct airflow, meaning the unit has shut down to ensure safe operation.
Your boiler's temperature sensors are providing conflicting or faulty data, so it has safely shut itself down to prevent overheating.
Your boiler has detected an issue with the sensor that measures the temperature of the water leaving for your radiators, causing it to stop heating safely.
Your boiler has temporarily stopped working because a temperature sensor measuring the heating water has registered a fault.
Your boiler's temperature sensor is providing faulty readings, causing the system to stop operating to prevent potential overheating.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the water returning from your radiators.
Your boiler has temporarily stopped working because it has detected an issue with the sensor that measures the temperature of the water returning from your radiators.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low.
Your boiler is struggling to understand how much water is inside it, so it has stopped working to prevent any potential damage.
Your boiler is currently unable to read its own internal water pressure, which prevents it from operating safely to provide heat or hot water.
Your boiler has automatically stopped working because the water pressure inside the system has risen higher than it should be.
Your boiler has detected an issue with how it manages water flow and pressure, which means it cannot safely produce hot water for your taps or home.
Your boiler has temporarily stopped working because it cannot properly read the water pressure inside the system.
Your boiler is temporarily locked out because it is getting an incorrect electronic signal from its internal water pressure monitoring system.
Your boiler is struggling to accurately read its internal temperature, so it has safely shut down to prevent overheating.
Your boiler is not able to accurately read the temperature of your hot water because a sensor is disconnected or faulty, which stops it from working properly.
Your boiler is temporarily unable to accurately measure your hot water temperature due to a faulty internal sensor.
Your boiler is struggling to read its internal water temperature correctly, so it has shut down to prevent overheating or system damage.
Your boiler is temporarily unable to accurately measure the temperature of the incoming cold water, which may affect its ability to provide stable hot water.
Your boiler is temporarily unable to accurately measure the temperature of the incoming cold water, which usually prevents it from heating water properly.
Your boiler is struggling to detect the movement of water, which means it cannot safely start heating your home or providing hot water.
Your boiler's main control computer is experiencing an internal electronic fault, preventing the system from operating correctly.
Your boiler's main control unit has temporarily lost the ability to 'talk' to its internal parts, meaning it has safely shut down to prevent unexpected behaviour.
Your boiler has lost its connection to the part responsible for creating the spark, meaning it cannot safely ignite to provide you with heating and hot water.
Your boiler has lost the connection between its main electronic brain and the internal fan that safely pushes out gases.
Your boiler's main electronic control unit has detected an internal monitoring or communication error, so it has safely shut down to prevent unexpected operation.
Your boiler has temporarily stopped working because the main control board has lost communication with its internal air and gas monitoring system.
Your boiler's main control board has lost communication with the valve that directs hot water between your taps and your radiators.
Your boiler's internal configuration settings are currently mismatched or incorrect, preventing the system from running properly.
Your boiler has detected an internal configuration error with its control board settings, meaning it cannot operate safely until corrected.
Your boiler's internal electronic systems are having trouble talking to each other, which means the device has stopped working to prevent further faults.
Your boiler has encountered an internal memory storage error, meaning it has lost its configuration settings and needs to be reset or repaired by a professional.
Your boiler's main computer control panel is failing to process instructions correctly, which has caused the system to stop operating for safety reasons.
Your boiler has detected a communication or safety data error regarding the temperature inside the main heat exchanger and has shut down to protect itself.
Your boiler has temporarily stopped working because it cannot properly read the temperature of the exhaust gases coming out of the flue.
Your boiler has detected an issue with the sensor that monitors the burner flame, so it has safely locked out to prevent unsafe operation.
Your boiler's main control unit has experienced an internal memory error, meaning it has lost its stored settings and cannot operate safely.
Your boiler has detected an incorrect reading from its internal water pressure sensor, which means it cannot safely verify the system pressure.
Your boiler has lost the connection to the thermometer installed outside your home, so it cannot automatically adjust your heating based on the current weather.
Your boiler has lost connection to the weather sensor outside, meaning it can no longer automatically adjust your heating temperature based on the weather.
Your boiler is receiving an incorrect signal from the optional outdoor weather sensor because of a wiring short, though your heating and hot water will still work.
Your boiler's internal electronic control boards are failing to talk to each other, which means the system cannot safely manage your heating or hot water.
Your boiler's main control panel has temporarily lost its connection, meaning it cannot talk to the internal parts needed to run your heating and hot water.
Your boiler is having trouble communicating with your wall-mounted thermostat or remote control panel, meaning it may not know when to turn on or off.
Your boiler's computer is having trouble restarting correctly after a software or power glitch, preventing it from functioning properly.
Not faults — these are normal operating states. Tap to expand.
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BoilerFaultCodes