99 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is currently working correctly and is simply letting you know that it is in central heating mode.
Your boiler is simply letting you know that it is currently busy heating up water for your taps or shower.
Your boiler is currently working to provide hot water to your taps and this code is simply a status update rather than a fault.
Your boiler is temporarily resting to prevent it from turning on and off too frequently, which helps protect the internal components from unnecessary wear.
Your boiler has temporarily paused its burner to prevent it from switching on and off too frequently, which helps protect the system from unnecessary wear.
Your boiler is working correctly and is simply waiting for a signal from your thermostat or timer to start heating.
Your boiler has sensed that the water temperature has risen above the level it was set to reach, leading it to shut down for safety.
Your boiler is currently set to a manual testing mode used by engineers to check emissions, which prevents it from operating normally.
Your boiler has detected that the internal fan is not spinning as expected during start-up, so it has safely shut down to prevent unsafe operation.
Your boiler has shut down because a safety sensor has detected that it is getting far too hot, likely due to a blockage or a pump failure.
Your boiler is failing to light the gas even though it is trying to, which prevents your heating and hot water from working.
Your boiler thinks a flame is burning even though it hasn't actually sparked or started, causing it to shut down for safety.
Your boiler's flame has gone out while it was trying to heat your water, which means the boiler has safely shut itself down to prevent any issues.
Your boiler has been intentionally switched off or put into standby mode by an external device, such as a smart thermostat, a programmer, or a safety control system.
Your boiler's computer is having trouble recognising its own internal settings, which is preventing it from starting up correctly.
Your boiler is not detecting the electrical connection to the gas supply mechanism, meaning it cannot safely ignite to provide heating or hot water.
Your boiler's internal computer is confused because its software settings don't match the specific model hardware installed.
Your boiler has detected a general internal communication failure, meaning it cannot safely operate its main control systems.
Your boiler's main control unit has identified an internal electronic error and has shut down to prevent potential damage.
Your boiler's main control unit is experiencing a communication error or electrical glitch that is preventing it from operating correctly.
Your boiler's main control computer is experiencing a temporary glitch or internal error, which has caused it to stop working for safety reasons.
Your boiler has detected an internal electronic communication error and has safely shut down to protect its system.
Your boiler has detected an internal electronic or control board communication error and has safely shut down to protect itself.
Your boiler has detected an internal electronic error with its main control board, which causes the system to stop working for safety.
Your boiler has detected an internal electronic error with its main control system and has safely shut down to prevent further issues.
Your boiler has detected an internal electronic communication error, meaning it has safely shut down to protect itself.
Your boiler has detected an internal electronic communication error and has safely shut down to protect its system.
Your boiler has detected an internal electronic error within its main control board, causing it to shut down safely.
Your boiler has detected an internal electronic communication error, which means it has safely shut down to prevent any further issues.
Your boiler has detected an internal electronic or control board issue that requires attention.
Your boiler's main control computer has encountered an internal electronic error and needs to be reset or inspected by a professional.
Your boiler has registered an internal electronic system error, meaning it has safely shut down to prevent further issues.
Your boiler has detected an internal electronic or control system error that is stopping it from operating safely.
Your boiler has detected an internal electronic communication error, meaning it has safely shut down to protect its main control system.
Your boiler's main control system has detected an internal communication or electronic error and has safely shut down to prevent further issues.
Your boiler has detected an internal electronic error with its main control board, which has temporarily shut it down for safety.
Your boiler has detected an internal electronic communication or control board fault, which stops it from working safely.
Your boiler is temporarily pausing because it is producing more heat than your home is currently asking for.
Your boiler has run a routine internal safety check on its main electrical switches, but it needs an engineer to clear the code and check the internal control board.
Your boiler has temporarily stopped working because it cannot reliably detect or keep the burner flame lit.
Your boiler has temporarily stopped working because the flame and internal airflow were unexpectedly interrupted.
Your boiler has detected that water is not circulating properly through the system because the internal pump is either jammed or trapped air is blocking the flow.
Your boiler is simply preparing to ignite and fire up its burner as part of its normal heating cycle.
Your boiler has detected an issue with the internal valve that controls the precise mix of air and gas needed for safe, efficient burning.
Your boiler has detected that a flame is still present briefly after the gas supply has been shut off.
Your boiler is running a temporary ventilation check to clear any stale air from the system before it attempts to fire up safely.
Your boiler is automatically running a routine cycle to prevent the internal pump from getting stuck, which is a normal maintenance feature.
Your boiler has detected an internal electronic communication error, meaning it has temporarily stopped working for safety.
Your boiler's main electronic control system has experienced an internal communication failure and cannot identify its own components.
Your boiler has detected an internal electronic or control board error and has safely shut down to prevent damage.
Your boiler has temporarily stopped working because the main electronic control system has detected an internal safety fault and shut down.
Your boiler is receiving incorrect temperature readings because a sensor attached to a specialist heating component is failing, which may temporarily stop your heating system from working properly.
Your boiler's internal control parts have temporarily lost their ability to talk to each other, which stops the system from working.
Your boiler has temporarily stopped working because it reached its maximum safe temperature limit during operation.
Your boiler's built-in service timer has gone off, which simply means it is time for its regular annual health check and service.
Your boiler has detected that the water pump connected to it does not match the correct specifications or settings required to run safely.
Your boiler is temporarily unable to accurately measure the temperature of your hot water cylinder due to a sensor or wiring issue.
Your boiler has been running continuously for too long and has safely paused itself as a precaution.
Your boiler has detected a problem with the temperature sensor that measures how hot the water is when it returns from your radiators.
Your boiler has lost connection with its outdoor temperature sensor, so it is running at a constant safe temperature to keep your home warm while it waits for a fix.
Your boiler is having trouble measuring either the outside temperature or the oxygen levels in the flue, which is preventing it from running efficiently or starting up correctly.
Your boiler is simply reminding you that its scheduled annual service is now due.
Your boiler is simply reminding you that its scheduled annual service is now due.
Your boiler is reminding you that its scheduled annual service is due, but it is still safe to use.
Your boiler has temporarily stopped working because a temperature monitoring sensor has detected an electrical wiring or internal fault.
Your boiler has temporarily stopped working because it has lost the electronic signal from one of its internal temperature sensors.
Your boiler's internal computer has encountered a critical electronic failure and can no longer communicate with its own sensors or controls.
Your boiler's internal computer has encountered a communication error or technical glitch that is preventing it from running properly.
Your boiler has detected an issue with how exhaust gases are being discharged, causing it to shut down for safety.
Your boiler's computer is having trouble communicating with its internal systems, which has caused it to shut down for safety reasons.
Your boiler has detected an internal electrical control system fault and has safely locked itself out to prevent further issues.
Your boiler has detected an internal electrical problem within its control system and has safely shut down to prevent further issues.
Your boiler has detected an issue with the flame and has shut down as a safety precaution to ensure no unburnt gas is escaping.
Your boiler has detected an unexpected electrical signal from the internal gas control system, which automatically shuts it down for safety.
Your boiler has detected a safety communication issue with the internal valve that controls the gas supply, meaning it has temporarily shut down to prevent any risk.
Your boiler has detected an unexpected electrical signal from its internal gas control component and has safely shut down.
Your boiler has detected an unexpected electrical signal from the internal gas control system and has safely shut down to prevent hazards.
Your boiler has tried to start up, but it cannot detect a steady flame to keep itself running safely.
Your boiler has detected an internal electronic error and has safely shut down to prevent further issues.
Your boiler's main computer has experienced an internal software error and has safely shut down to prevent incorrect operation.
Your boiler has detected that the electrical voltage supplying the internal burner control is too low, causing it to safely shut down to prevent damage.
Your boiler's computer brain has detected an internal electronic chip that doesn't match the model or has become loose.
Your boiler temporarily failed to detect a flame during a low-power start, often caused by strong outside winds blowing down the flue.
Your boiler has temporarily stopped because external conditions like strong winds are interfering with its exhaust, but it should restart automatically once the air clears.
Your boiler tried to start up, but it couldn't detect a flame to keep it burning.
Your boiler is repeatedly failing to keep its internal flame lit, so it has safely shut itself down to prevent gas from building up.
Your boiler has detected an internal error while trying to confirm it is burning fuel correctly, and it has shut down as a safety precaution.
Your boiler has detected an incorrect or incompatible internal configuration setting, which stops it from operating safely.
Your boiler's internal settings or water system configuration have not been properly recognized, which stops it from operating correctly.
Your boiler's internal electronic control system has identified a technical failure that requires an expert to reset or replace the faulty circuit board.
Your boiler is unable to detect that its internal air fan is spinning, so it has safely shut itself down to prevent operation without proper ventilation.
Your boiler has stopped working because it cannot confirm that the internal fan, which is essential for safely exhausting gases, is running correctly.
Your boiler has stopped working because it cannot move the air and exhaust gases through the system properly.
Your boiler has detected that the sensors monitoring its internal temperature are giving incorrect readings or have failed, causing the system to shut down for safety.
Your boiler has sensed that the water inside is getting much hotter than it should be and has shut down as a safety precaution.
Your boiler is overheating too quickly because water isn't moving through the system fast enough.
Your boiler is struggling to work because the electricity supply coming from your home's wall socket or wiring is weaker than it needs to be.
Your boiler has locked itself for safety due to a temporary operational issue, which can often be cleared by following the on-screen reset instructions.
Your boiler has experienced a safety lockout and needs you to try resetting it, or call an engineer if the lockout persists.
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BoilerFaultCodes