129 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Potterton Suprima HE
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
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Your boiler has reached its target temperature and is simply resting until it needs to heat up again.
Your boiler has likely overheated or a sensor has detected an incorrect temperature, causing the system to shut down for safety.
Your boiler has switched itself off because it has become too hot internally and needs to cool down for safety.
Your boiler is struggling to keep its burner lit and is trying to restart itself automatically.
Your boiler is failing to light its burner after five attempts, which means it cannot provide heat or hot water and has gone into lockout for safety.
Your boiler is having a temporary 'conversation' issue between its internal parts and should fix itself momentarily.
Your boiler has detected that its internal fan is not spinning correctly, which means it cannot safely vent exhaust gases and has shut down as a precaution.
Your boiler has experienced a brief electronic 'hiccup' or data error and is trying to clear itself automatically.
Your boiler's computer memory has developed a technical fault, causing the system to lock out for safety.
Your boiler has experienced a brief internal glitch and is currently attempting to restart itself automatically.
Your boiler has detected an internal communication error and has shut down as a safety precaution.
Your boiler has stopped working because the internal fan is not running at the correct speed to safely clear waste gases.
Your boiler is not receiving enough electrical power from the mains supply to operate safely.
Your boiler has got too hot and has shut itself down for safety reasons.
Your boiler's internal computer has developed a fault and can no longer control the heating process safely.
Your boiler's internal computer brain has developed a terminal fault and can no longer control the heating process safely.
Your boiler has detected that water is either not moving through the system properly or there is no water inside the unit, causing it to overheat quickly.
Your boiler has likely stopped heating because a temperature sensor is sending incorrect information to the main control board.
Your boiler has detected an electrical wiring issue, meaning the power supply polarities are the wrong way around and need correcting for safety.
Your boiler's internal computer has developed a fault and can no longer control the heating process safely.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler has too much water in the system, which puts extra stress on the internal pipes and components.
Your boiler has stopped working because there is not enough water pressure in the system to operate safely.
Your boiler has stopped working because the water pressure in the central heating system has dropped too low to operate safely.
Your boiler has stopped working because the water isn't moving through the system properly, which is causing it to overheat and shut down.
Your boiler hasn't been able to heat the water hot enough to kill off harmful bacteria in the system, which is a safety setting meant to keep your water clean.
Your boiler started to heat up but the flame went out unexpectedly while it was running.
Your boiler has failed to light the gas flame after several attempts, which has caused the system to shut down for safety.
Your boiler's internal computer has been reset too many times in a short period and has temporarily locked itself for safety.
Your boiler has detected that its internal fan is not spinning correctly, which means it cannot safely blow away waste gases and has shut down as a result.
Your boiler has detected an issue with how air is moving through the system, meaning it cannot safely clear waste gases and will not fire up.
Your boiler has detected that water is not moving through the system correctly or a sensor that monitors water flow has failed.
Your boiler has detected an issue with the airflow system which is preventing it from firing up safely.
Your boiler has detected that it is trying to heat up without enough water flowing through it, which could cause the unit to overheat.
Your boiler has lost its electrical ground connection, which is a vital safety feature that prevents electrical faults.
Your boiler has switched itself off because the water inside the main heating unit has reached a dangerously high temperature.
Your boiler has detected that a temperature sensor is disconnected or faulty, which prevents it from monitoring the water heat levels safely.
Your boiler has stopped working because it cannot correctly measure the temperature of the water returning from your radiators.
Your boiler has detected that the water coming back from your radiators is hotter than the water going out, which usually means a sensor is failing or the water flow is mixed up.
Your boiler is repeatedly struggling to keep the burner flame lit, forcing the system to shut down for safety.
Your boiler's fan is not spinning at the correct speed to safely clear exhaust fumes, which could be caused by strong winds outside or a mechanical fault.
Your boiler has sensed that the cool water returning is hotter than the water leaving, which usually means the water isn't circulating correctly or a sensor is misreading.
Your boiler has likely stopped working because water isn't moving through the system properly or a temperature sensor has a loose connection.
Your boiler has shut down because a sensor thinks the exhaust gases are getting too hot, usually because water isn't flowing through the system properly.
Your boiler is simply notifying you that the reset button was recently held down or pressed.
Your boiler has stopped working because there is not enough water pressure in the system to operate safely.
Your boiler's internal computer has suffered a serious electronic failure and can no longer control the heating process safely.
Your boiler's internal computer has lost contact with the gas control unit, meaning the system cannot safely manage the fuel it needs to stay alight.
Your boiler's electronic control board has detected a configuration setting error, likely caused by a component fault or an incorrect setup after a repair.
Your boiler's electronic control board has detected an internal configuration error, likely due to a component change or a settings mismatch.
Your boiler's electronic control board has detected a configuration setting change that is preventing it from starting up properly.
Your boiler is having trouble communicating with external controls like your thermostat or programmer, preventing it from heating your home.
Your boiler is having trouble communicating with your thermostat or external programmer, meaning it cannot receive the signal to turn on.
Your boiler has lost communication with the internal gas valve, which means it cannot ignite to provide heat or hot water.
Your boiler has stopped working because it cannot correctly measure the temperature of the water leaving the unit.
Your boiler has stopped working because it cannot accurately measure the temperature of the water leaving the unit, usually due to a faulty sensor or a loose internal wire.
Your boiler has reached an unsafe temperature because the water inside isn't moving through the system properly.
Your boiler has detected a problem with the sensor that monitors exhaust gases, causing the system to shut down for safety.
Your boiler has detected a problem with the sensor that monitors exhaust gases, causing it to shut down for safety.
Your boiler has shut down because it is getting too hot inside, which is likely caused by water not moving properly or a faulty safety sensor.
Your boiler has switched itself off because it has detected it is getting too hot or there is a problem with the internal safety sensors.
Your boiler has failed to ignite, which means it cannot heat the water needed for your radiators or taps.
Your boiler thinks it sees a flame when it shouldn't, which is preventing it from starting safely to protect your home.
Your boiler has stopped working because the fan that clears away waste gases is jammed or cannot turn.
Your boiler has detected a serious internal hardware failure involving its gas supply system and cannot safely ignite.
Your boiler has stopped working because it cannot accurately measure the temperature of the water inside the system.
Your boiler has got too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler has stopped because the water isn't flowing through the pipes and radiators properly, likely due to trapped air or a blockage.
Your boiler’s internal control board has developed an electrical error and is unable to manage the heating process correctly.
Your boiler is struggling to light and stay on, which might be caused by trapped air in your heating system stopping the water from flowing properly.
Your boiler has lost its electrical connection to the gas control valve, meaning it cannot safely ignite to provide heat or hot water.
Your boiler has lost communication with the sensor that monitors outside temperature, which means it doesn't know how hard it needs to work to heat your home.
Your boiler is struggling to detect if water is moving through the system properly, which is preventing it from heating up for safety reasons.
Your boiler has detected that a internal water flow sensor is stuck in the 'on' position even when the pump is off, preventing the system from starting safely.
Your boiler has detected an internal electrical communication error between the main control board and the gas valve, preventing it from lighting safely.
Your boiler's internal temperature sensor has stopped sending a reliable signal, which means it cannot safely tell how hot the water is for your heating.
Your boiler has detected a problem with how it releases exhaust gases or a fault with an internal sensor, causing it to shut down for safety.
Your boiler has detected an issue with the sensor that monitors the temperature of the water returning from your radiators.
Your boiler has lost its connection to the sensor that monitors hot water temperature, meaning it can no longer safely heat your water.
Your boiler is not getting enough air to burn gas safely, which often means the external exhaust pipe is obstructed.
Your boiler is having trouble detecting when you turn on your hot taps, which may prevent the water from heating up properly.
Your boiler’s internal computer has lost its timing settings and needs to be recalculated to ensure the gas burns correctly.
Your boiler has lost track of the water pressure inside the system because the internal sensor is either faulty or disconnected.
Your boiler's main control board has lost contact with its user display or internal sensors, meaning it cannot receive instructions to provide heating or hot water.
Your boiler has detected an issue with the fuel and air mixture while trying to calibrate itself, meaning it cannot start the burner safely.
Your boiler's main control board has lost track of the time or date, which is preventing it from running its scheduled heating cycles.
Your boiler is struggling to move water around the system effectively, which is causing it to stop to prevent overheating.
Your boiler has shut down because it has detected it is getting too hot, triggering a safety switch to prevent damage.
Your boiler has stopped working because the water pressure inside the system is too high.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Your boiler has stopped working because the water pressure is too low for the system to run safely.
Your boiler is overheating because the water is not moving around the pipes properly.
Your boiler is struggling to keep the flame lit and has repeatedly shut down after several failed attempts to stay running.
Your boiler is struggling to keep a steady flame during its startup process and has stopped for safety reasons.
Your boiler has detected that the exhaust gases are getting too hot or the sensor monitoring them has failed, causing the system to shut down for safety.
Your boiler has switched itself off because the temperature in the exhaust flue has become dangerously high, which is a safety mechanism to prevent damage.
Your boiler has failed to light because it either cannot get any gas or the internal sensor cannot detect the flame.
Your boiler has tried to ignite several times but failed to establish a flame, often due to a temporary interruption in the gas supply or a sensor issue.
Your boiler has stopped working because the gas supply has been interrupted or the internal controls are failing to detect the flame.
Your boiler has detected that the water temperature readings are inconsistent, which usually means water isn't circulating correctly through the system.
Your boiler has detected a problem with the fan that clears away waste gases, causing the system to shut down for safety.
Your boiler has detected a problem with its internal fan, which is preventing it from safely clearing exhaust gases and starting up.
Your boiler has lost its connection to the sensor that monitors hot water temperature, meaning it can no longer safely heat water for your taps.
Your boiler is having trouble monitoring its internal water pressure, which prevents it from firing up and heating your home.
Your boiler's internal computer has developed a fault and can no longer communicate with the rest of the system.
Your boiler's internal computer has encountered a memory error and has stopped working to prevent further issues.
Your boiler is struggling to move water through the system properly before it begins the heating process.
Your boiler is overheating because water isn't moving through the system properly, causing it to shut down for safety.
Your boiler has detected an issue with the electrical power timing coming from the mains supply or an internal electronics failure.
Your boiler has lost its ability to measure the temperature of your hot water properly, which means it cannot safely heat your water to the right level.
Your boiler thinks a flame is burning when it shouldn't be, causing the system to shut down for safety.
Your boiler is not receiving enough electrical power to run correctly, causing it to shut down for safety.
Your boiler is temporarily checking if there is enough water pressure in the system to operate safely.
Your boiler has lost its connection to the gas valve, meaning it cannot safely control the fuel needed to start the flame.
Your boiler is overheating because water isn't moving through the system quickly enough or a sensor is giving a false reading.
Your boiler is overheating or water is not moving through the system quickly enough to be cooled down.
Your boiler has sensed it is getting too hot too quickly, likely because the water isn't moving through the system properly.
Your boiler has detected that water isn't moving through the system properly or a sensor is getting a strange temperature reading, so it has shut down to prevent overheating.
Your boiler is shutting down because the water inside is heating up too quickly, which usually means it isn't moving through the system properly.
Your boiler's internal computer brain hasn't been programmed with the correct settings and doesn't know how to operate.
Your boiler's computer brain is momentarily confused by its internal setup and needs to be refreshed or reconfigured.
Your boiler's computer system has encountered a temporary settings error and is struggling to communicate with its internal components.
Your boiler has detected that the water pressure is too low or leaky, causing it to shut down to prevent damage.
Your boiler is having trouble 'talking' to its internal temperature sensors, which is preventing it from heating your home safely.
Your boiler’s internal computer is having trouble talking to its other components, causing the system to stop working for safety.
Your boiler has lost its flame while it was running and has safely turned itself off to prevent a problem.
Your boiler appears to have no electrical power at all, meaning the screen and internal components are completely switched off.
Your boiler has tried to light several times but failed, so it has locked itself for safety.
Your boiler has detected an internal electrical communication problem and has stopped working to prevent further damage.
BoilerFaultCodes