129 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Potterton Promax HE Store
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 required temperature and has temporarily stopped heating until it needs to kick in again.
Your boiler has detected that it is getting too hot or that water isn't moving through the system correctly, causing it to shut down for safety.
Your boiler has become too hot and has automatically shut itself down to prevent damage.
Your boiler has temporarily lost its flame and is attempting to restart itself automatically.
Your boiler is failing to light its burner to create heat after several attempts, which means it has locked itself out for safety.
Your boiler is having a temporary glitch in its internal electronic communication and is attempting to fix itself.
Your boiler's internal fan is failing to start or run at the correct speed, which means the system cannot safely clear waste gases and has shut down as a precaution.
Your boiler's internal computer has encountered a momentary glitch in its settings but should fix itself automatically.
Your boiler's internal memory chip is failing to communicate with the main control board, preventing the system from starting up.
Your boiler is experiencing a temporary glitch and is currently trying to fix itself by restarting.
Your boiler has encountered a general electrical or internal communication error and has shut down as a safety precaution.
Your boiler has stopped working because the fan that helps remove waste gases is either stuck or not communicating correctly with the main control board.
Your boiler is not receiving enough electrical power from the mains supply to operate safely.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler's main internal computer has developed a fault and can no longer control the heating process safely.
Your boiler’s internal control brain has developed a critical fault and is unable to communicate with the rest of the system.
Your boiler has detected that water isn't moving through the system properly or there is no water inside the unit, causing it to overheat quickly.
Your boiler has detected a sensor failure and has stopped working to prevent itself from overheating.
Your boiler has detected an electrical configuration issue where the power wires are connected the wrong way round.
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 down as a safety precaution to prevent damage.
Your boiler has too much water in the system, which puts unnecessary stress on the pipes and internal components.
Your boiler has stopped working because there is not enough water pressure in the central heating system to operate safely.
Your boiler has stopped working because the water pressure in the heating system has dropped too low.
Your boiler has stopped working because water is not moving through the system properly, which causes it to overheat and shut down for safety.
Your boiler has failed to heat the water storage tank to a high enough temperature to kill off potentially harmful bacteria.
Your boiler started to heat up but the flame went out unexpectedly while it was running.
Your boiler has tried to light several times but has been unable to sustain a flame, meaning your heating and hot water will not work.
Your boiler has been manually reset but may have a deeper component issue that is preventing it from staying on.
Your boiler has stopped working because the internal fan, which safely exhausts waste gases, is not spinning correctly or communicating with the control board.
Your boiler has detected an issue with the airflow required to safely exhaust fumes, causing it to shut down for safety.
Your boiler has detected that water is not circulating correctly through the system, which is preventing it from heating up safely.
Your boiler has stopped working because it cannot confirm that its fan is moving air safely through the system.
Your boiler has detected that it is heating up without enough water inside it, causing it to shut down to prevent internal damage.
Your boiler has detected an electrical grounding issue which is preventing it from starting up safely.
Your boiler has shut down because the water inside it has become dangerously hot, likely because it isn't circulating through your radiators properly.
Your boiler has stopped working because it cannot correctly measure the temperature of the water returning to the unit.
Your boiler has detected a problem with the sensor that monitors water temperature returning to the unit, causing the system to shut down for safety.
Your boiler is confused because the pipe leading back to the unit is showing a higher temperature than the pipe sending heat out, which usually means water is flowing the wrong way or a sensor is faulty.
Your boiler is struggling to keep a flame lit and has safely shut down after multiple failed attempts to stay running.
Your boiler's fan isn't spinning at the right speed to safely clear waste gases, which may be caused by strong winds outside or a mechanical fault.
Your boiler has sensed that water returning to the unit is hotter than the water leaving it, which indicates a circulation problem that requires a manual reset.
Your boiler has stopped working because water is not moving through the system or a sensor has become disconnected.
Your boiler has shut down because it is getting too hot, likely due to water not moving through the system properly or a faulty safety sensor.
Your boiler is simply acknowledging that the reset button has been pushed and is restarting its normal cycle.
Your boiler has detected that there is not enough water in the central heating system to operate safely.
Your boiler’s internal computer has suffered an electronic failure and can no longer communicate with the heating system.
Your boiler has lost the ability to control the gas flow properly due to an internal communication failure between the control board and the gas unit.
Your boiler's electronic control board has detected an internal configuration setting that doesn't match the expected setup, often occurring after a power surge or a part replacement.
Your boiler's main control board has detected a configuration setting error, meaning it isn't sure which specific model it is supposed to be operating as.
Your boiler’s internal control board has detected a configuration error, likely caused by a hardware setting being incorrectly changed during a repair or a component failing.
Your boiler is having trouble communicating with external controls like your thermostat or programmer due to a connection or wiring issue.
Your boiler is having trouble communicating with your thermostat or other smart home controllers.
Your boiler has lost its connection to the gas control unit, meaning it cannot safely ignite to provide heating or hot water.
Your boiler has stopped working because it cannot correctly measure the temperature of the water leaving the unit.
Your boiler has lost its connection to the sensor that monitors internal water temperature, meaning it cannot safely heat your home until the part is checked or replaced.
Your boiler has shut down because it is getting too hot too quickly, likely due to water not moving through the system properly.
Your boiler has detected a problem with the sensor that monitors exhaust gases, causing it to shut down for safety.
Your boiler has detected a problem with the sensor that monitors the safety of your exhaust gases, causing the system to shut down for protection.
Your boiler has reached an unsafe temperature or the air circulation is blocked, causing the system to shut down for safety.
Your boiler has switched itself off because it has detected it is getting too hot, likely due to a blockage, a pump problem, or a faulty sensor.
Your boiler has failed to ignite, meaning it is unable to create a flame to provide heat or hot water.
Your boiler thinks it can see a flame when there shouldn't be one, or it is getting incorrect electrical signals, causing it to shut down for safety.
Your boiler's fan has stopped spinning, which means it cannot safely clear exhaust gases and will not start the ignition process.
Your boiler has detected a serious internal communication error or a mechanical failure with the gas system, meaning it cannot safely light itself to provide heating or hot water.
Your boiler has detected an issue with the sensor that monitors internal water temperature, preventing it from heating up correctly.
Your boiler has become too hot and has shut down as a safety precaution to prevent damage.
Your boiler is struggling to move water around the system, which is causing it to overheat and shut down for safety.
Your boiler's internal computer has developed an electrical fault and is unable to control the heating process safely.
Your boiler has tried to light several times but has failed to create a steady flame, meaning your heating and hot water won't work.
Your boiler has stopped working because it cannot communicate properly with the gas valve that controls the fuel supply.
Your boiler has lost communication with the outdoor temperature sensor, meaning it may not know how hard it needs to work to heat your home.
Your boiler has detected that water isn't moving through the system properly or a safety sensor is failing to register the flow.
Your boiler has detected that a water flow sensor is stuck in the 'on' position, preventing the system from starting its safety checks correctly.
Your boiler's internal computer is having trouble communicating with the mechanism that controls the gas supply, meaning it cannot ignite safely.
Your boiler's internal temperature sensor has stopped sending the correct information to the control board, preventing the system from heating up safely.
Your boiler has detected an issue with the sensors that monitor exhaust gases or air flow, 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 ability to monitor the temperature of your hot water due to a sensor fault, which prevents the system from heating it safely.
Your boiler is struggling to burn gas safely because the air supply or exhaust pipe is likely obstructed.
Your boiler is struggling to detect when you turn on a hot tap, meaning you might have inconsistent or no hot water.
Your boiler has lost its fine-tuned settings and needs to be recalibrated to run safely and efficiently.
Your boiler has lost the ability to monitor its own water pressure, meaning it has shut down as a safety precaution while it is unable to tell if there is enough water to operate safely.
Your boiler's main control board has lost contact with the digital interface, meaning the internal components can no longer talk to each other to start the heating process.
Your boiler has failed to calibrate its burning process correctly and has shut down as a safety precaution.
Your boiler's internal computer has lost track of the time or is struggling to communicate with its built-in clock, which may prevent it from running its scheduled cycles.
Your boiler has detected that water is not moving through the system properly, which is causing it to shut down to prevent overheating.
Your boiler has likely overheated, causing a safety switch to kill the power to prevent any damage.
Your boiler has detected that there is too much water pressure in the system, which can cause the safety valve to leak or the unit to stop working.
Your boiler has stopped working because the water pressure in the central heating system has dropped too low.
Your boiler has lost water pressure, which means there isn't enough water inside the system for it to run safely.
Your boiler is struggling to move heated water through the system, often caused by a blockage or a pump failure.
Your boiler is repeatedly losing its flame and has locked itself out after too many failed attempts to stay lit.
Your boiler is struggling to keep a steady flame alight and has failed to automatically adjust itself after several attempts.
Your boiler has shut down because a sensor has detected that the exhaust gases are getting too hot, or the sensor itself has failed.
Your boiler has switched itself off because the exhaust gases have become too hot, which is a safety measure to prevent damage to the internal components.
Your boiler is not receiving enough gas or is struggling to light the flame needed to generate heat.
Your boiler has failed to ignite several times in a row, often because the gas supply is interrupted or the burner isn't catching the spark.
Your boiler has stopped working because the internal gas supply has been interrupted, meaning the burner cannot stay lit.
Your boiler has detected that the water temperature readings are inconsistent, which usually means the water isn't circulating properly through the system.
Your boiler has detected a problem with the fan that clears away waste gases, meaning the system has shut down for safety.
Your boiler has detected a problem with the fan that safely clears away exhaust gases, meaning the system has shut down as a safety precaution.
Your boiler has lost its connection to the hot water temperature sensor, meaning it cannot monitor how hot the water is and will likely stop producing hot water for safety.
Your boiler has detected an issue with its internal sensor that monitors water pressure, preventing it from heating your home safely.
Your boiler's internal computer has developed a fault and is struggling to communicate with the rest of the unit.
Your boiler's internal computer has encountered a generic system error and has stopped working to protect itself.
Your boiler has noticed that water isn't moving through the system properly before it attempts to ignite, usually due to a blockage or a pump issue.
Your boiler has sensed it is getting too hot too quickly, usually because water isn't moving through the system properly to carry the heat away.
Your boiler is struggling to operate because the incoming electricity frequency does not match the required standard for its internal computer.
Your boiler has detected a problem with the sensor that monitors hot water temperature, meaning it cannot safely heat water for your taps.
Your boiler thinks there is a flame present when there shouldn't be, which is preventing it from starting up safely.
Your boiler is not receiving enough electrical power to operate correctly, which has caused it to shut down for safety.
Your boiler is temporarily checking if there is enough water pressure to operate safely.
Your boiler has lost its internal connection to the part that controls the gas flow, meaning it cannot ignite safely to provide heating or hot water.
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 heating up too quickly because water isn't moving through the system properly, causing it to shut down to prevent damage.
Your boiler has shut down because it is getting too hot too quickly, usually because water isn't moving through the system properly.
Your boiler is overheating because water is not moving through the system properly or a sensor has detected an incorrect temperature reading.
Your boiler is heating up much too quickly and has shut itself down to prevent damage, likely because the water isn't moving through the system fast enough.
Your boiler’s internal computer chip has lost its memory and needs to be told how to work correctly again.
Your boiler's internal computer is having a temporary communication problem with its settings and needs a simple reset to reconnect.
Your boiler's computer memory has become confused or corrupted, causing it to stop because it no longer recognizes its own internal settings.
Your boiler has detected that the water pressure is either too low or there is a leak somewhere in the heating system, causing it to stop working.
Your boiler has stopped working because its internal computer has lost contact with one of the temperature sensors.
Your boiler's internal computer is having trouble communicating with the rest of the unit, meaning it cannot process instructions to heat your home.
Your boiler has lost its flame while it was running, meaning it has shut down because it can no longer safely heat your water.
Your boiler has no power and is completely shut down, which means your heating and hot water will not work.
Your boiler has tried to light several times but failed, so it has shut itself down for safety.
Your boiler has detected an internal electrical communication problem between its main control components.
BoilerFaultCodes