94 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is struggling to operate its internal fan correctly, which prevents it from firing up safely.
Your boiler has detected an electrical fault in its internal wiring, which has caused it to shut down for safety reasons.
Your boiler has detected that a flame is still present even though it has commanded the gas to turn off, which poses a significant safety risk.
Your boiler has failed to light because it cannot detect a flame, meaning you currently have no heating or hot water.
Your boiler's internal computer settings have become scrambled, preventing it from understanding how to safely start or run.
Your boiler is struggling because electrical interference from nearby devices or poor wiring is disrupting its computer systems.
Your boiler has experienced a power interruption following an earlier, currently hidden problem that caused it to shut down for safety.
Your boiler is operating normally and these numbers represent the current stage of the heating or hot water production process.
Your boiler has detected a general internal error and has paused operation as a safety precaution.
Your boiler has lost the ability to send signals between its internal controls, likely due to a loose wire or moisture inside the display unit.
Your boiler has detected that the water returning to it is much hotter than expected, so it has shut down to prevent overheating.
Your boiler has shut down because it cannot circulate enough water to keep the internal heat at a safe level.
Your boiler has detected an issue with the internal fan that pushes air through the system, causing it to stop its normal operation to prevent a safety risk.
Your boiler has detected that the internal fan is not spinning, so it has safely shut itself down to prevent any risk of incomplete combustion.
Your boiler is confused because it detects that the water is circulating in the wrong direction or the pipes are connected the wrong way round.
Your boiler has stopped working because it cannot correctly read the temperature of the water flowing through it, so it has shut down as a precaution.
Your boiler has detected a faulty signal from one of its internal heat sensors, causing it to stop operating as a safety precaution.
Your boiler has lost its connection to a temperature probe, meaning it cannot accurately monitor the water circulating back into the system, causing the unit to shut down to prevent potential overheating.
Your boiler has stopped working because it has lost contact with the internal component that measures how hot the water is.
Your boiler has lost the signal from the weather sensor outside, which means it cannot automatically adjust your heating based on the outdoor temperature.
Your boiler is struggling to ignite or maintain its higher power setting, which is usually caused by an issue with the gas supply or internal components.
Your boiler has detected an incorrect internal setting that prevents it from starting up correctly.
Your boiler is currently running at its initial power setting and is functioning as expected during the start-up phase.
Your boiler is failing to stay lit because it cannot reliably detect a flame or is struggling to breathe properly through its flue system.
Your boiler has lost its electrical power supply or its internal control board is not receiving electricity.
Your boiler's internal computer brain has developed a critical error and is unable to control the heating process safely.
Your boiler has detected a potential internal gas leak or a fault with the valves that control gas flow, causing the system to shut down for safety reasons.
Your boiler has detected a safety issue with its internal systems and has shut itself down to prevent any damage or danger.
Your boiler is failing to light the flame or keep it burning, which means your heating and hot water have stopped working.
Your boiler's main internal computer has developed a serious fault and is no longer able to manage the heating system safely.
Your boiler’s internal computer has suffered an electrical internal failure and can no longer control the heating process safely.
Your boiler has detected that there is not enough water pressure or flow to operate safely and has shut down to prevent overheating.
Your boiler's main internal computer has developed a serious fault and is no longer able to manage the heating process safely.
Your boiler's internal computer brain has developed a serious fault and can no longer control the heating safely.
Your boiler has detected that dangerous exhaust fumes are being pushed back into the appliance instead of flowing out through the flue.
Your boiler's internal computer has encountered a critical error and can no longer control the heating system safely.
Your boiler has detected that there isn't enough water pressure or flow inside the system to operate safely.
Your boiler has shut down because it has detected an unsafe build-up of heat or a lack of water circulation within the system.
Your boiler has detected an incorrect reading from a internal temperature sensor, causing it to stop operating as a safety precaution.
Your boiler's internal computer has encountered a critical electronic malfunction and can no longer safely control the heating process.
Your boiler's internal computer brain has encountered a critical error and can no longer control the heating system safely.
Your boiler's main internal computer has developed a serious fault and is no longer communicating correctly with the rest of the system.
Your boiler is temporarily pausing and cooling down to a specific starting temperature because its internal controls have told it to stop heating for a moment.
Your boiler has temporarily stopped because it reached its maximum safe operating temperature and needs to cool down before restarting.
Your boiler is failing to start because it cannot detect that the air fan is spinning at the required speed to operate safely.
Your boiler is struggling to get the air flowing properly to ensure safe combustion, and after several repeated failed attempts, it has turned itself off for safety.
Your boiler is overheating because it cannot move the hot water away fast enough, so it has temporarily turned itself off to cool down.
Your boiler has detected that an external safety device, such as a high-limit thermostat or a flue gas monitor, has temporarily broken the electrical circuit, causing it to pause operations for safety.
Your boiler has temporarily stopped because the temperature difference between the water going out and coming back is too high, often due to restricted water flow.
Your boiler has temporarily stopped because it cannot move heat away from its internal components fast enough, which often points to restricted water flow in your radiator system.
Your boiler's internal settings have been altered or corrupted, causing it to stop functioning until these values are corrected.
Your boiler has stopped working because the fan is spinning faster than it should, which has caused the system to shut down for safety.
Your boiler has detected that the water temperature sensors are reading back-to-front, which usually means there is a wiring issue or the water is flowing in the wrong direction.
Your boiler is heating up too quickly, which usually means the water is trapped or not moving through the system properly.
Your boiler has detected that there is not enough water in the system or the water is not moving around properly to keep it running safely.
Your boiler has stopped working because its internal fan is not spinning fast enough to safely clear out exhaust gases.
Your boiler has detected a problem with how fast its internal fan is spinning, which is preventing it from running safely.
Your boiler has detected that the water is heating up too quickly or isn't circulating properly through the system.
Your boiler's computer memory has incorrect settings or corrupted data, causing it to stop running for safety.
Your boiler is not firing up because it cannot detect an active call for heat or there is an issue with the electrical power supply reaching the unit.
Your boiler is trying to light but failing to detect a flame, which means it has shut down for safety because there is either a gas supply issue or a sensor fault.
Your boiler has temporarily stopped because it is waiting for the system to reach the correct temperature or a specific safety condition to be met before restarting.
Your boiler's internal computer has encountered a serious internal error and has shut down to prevent further damage.
Your boiler’s internal computer has suffered a memory failure and can no longer process instructions or run safely.
Your boiler has failed to start its flame successfully after several attempts, so it has turned itself off for safety.
Your boiler has stopped working because it cannot correctly read the temperature of the water leaving the unit.
Your boiler is trying to start but cannot detect a flame, so it has safely shut itself down to prevent gas from building up.
Your boiler has detected a fault with the sensor that monitors water returning from your radiators, causing the system to shut down for safety.
Your boiler is detecting a flame inside the unit even before it has tried to start up, which prevents it from operating safely.
Your boiler has stopped working because it can no longer accurately measure the temperature of the water leaving the unit.
Your boiler has successfully lit the flame, but it is repeatedly going out while running, causing the system to lock itself for your safety.
Your boiler has stopped working because it cannot accurately measure the temperature of the water returning to the unit.
Your boiler is struggling to push air through for combustion, so it has safely shut itself down to prevent ignition problems.
Your boiler has sensed that the water circulating through the system is getting far too hot, causing it to shut down to prevent damage.
Your boiler has stopped heating because it has lost the ability to read the temperature of the water flowing through it due to a faulty electrical connection or sensor.
Your boiler has shut down because the water returning from your radiators is too hot, meaning the system cannot circulate heat correctly.
Your boiler has stopped working because it is unable to accurately measure the temperature of the water returning to it, so it has shut down to protect itself.
Your boiler is heating up much faster than it should because water isn't flowing through the system correctly.
Your boiler is confused because it senses the water temperatures are flowing in the wrong direction or are unevenly matched.
Your boiler is overheating because water isn't moving through the system quickly enough, making the outgoing pipe much hotter than the return pipe.
Your boiler has detected an issue with the internal component that regulates and monitors its gas supply, meaning it will remain safely shut down until a professional can inspect it.
Your boiler has sensed that water isn't moving through the system quickly enough, causing a sudden heat imbalance when it tries to fire up.
Your boiler has detected that the water pressure inside the system is currently too low to operate safely, causing it to shut down to prevent damage.
Your boiler has detected that the water inside the system is getting too hot or is not circulating properly, so it has safely shut down to prevent damage.
Your boiler's electronic control panel is having trouble talking to its main internal brain, meaning the system has shut down for safety.
Your boiler's internal computer is struggling to read or save its saved settings, which means it has safely shut down to prevent incorrect operation.
Your boiler has detected a faulty reading from its temperature monitor, so it has safely shut down to prevent potential overheating.
Your boiler has detected that the exhaust gases are becoming dangerously hot and has shut itself down to prevent overheating damage.
Your boiler's main internal computer has encountered a critical electronic failure and can no longer control the heating process safely.
Your boiler's main control system has experienced a software or communication error and cannot operate safely.
Your boiler is temporarily prioritizing its internal frost protection system over your normal heating settings, causing a communication mix-up.
Your boiler has detected an internal computer error which has caused it to shut down to prevent damage.
Your boiler is currently performing a standard task, such as heating your radiators or hot water, and is operating exactly as it should.
Your boiler is currently set to a special configuration mode used by engineers for testing or setup, rather than operating in normal heating mode.
BoilerFaultCodes