129 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Baxi Potterton Assure
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 →
Tap any card for details
Your boiler is working normally and has simply reached the correct temperature to heat your home or water.
Your boiler has detected that it is getting too hot or that water isn't moving through the system properly, causing it to shut down for safety.
Your boiler has become too hot and has automatically shut down to prevent damage.
Your boiler is temporarily losing its flame and is currently attempting to fix the issue itself.
Your boiler is failing to light the gas flame after several attempts, which means it will stay locked out to keep you safe.
Your boiler is having a temporary 'handshake' problem between its internal electronics which should resolve itself automatically.
Your boiler has stopped working because the fan that helps remove waste gases is not running correctly.
Your boiler has experienced a brief glitch in its internal electronic settings and is currently trying to fix itself automatically.
Your boiler's internal memory chip has failed or lost its settings, meaning the unit can no longer communicate with its own control board.
Your boiler has encountered a minor temporary glitch and is currently trying to reset itself automatically.
Your boiler has encountered an internal electronic error that is preventing it from starting up correctly.
Your boiler's internal fan is failing to start or run correctly, which means the system cannot safely clear away waste gases and has shut down as a precaution.
Your boiler is not receiving enough electrical power from your home's supply to operate safely.
Your boiler has become too hot and has automatically shut down as a safety precaution to prevent damage.
Your boiler's internal computer has encountered a critical error and can no longer control the heating system safely.
Your boiler’s internal control board has suffered a critical failure and can no longer safely operate the system.
Your boiler is struggling to move water around the system or has detected it is heating up too quickly without enough water inside.
Your boiler has detected a problem with its internal temperature sensors and has stopped working to prevent overheating.
Your boiler has detected an electrical wiring issue where the power supply wires are connected the wrong way around, preventing it from starting for safety reasons.
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, causing the pressure to rise above a safe level.
Your boiler has stopped working because the water pressure in the system has dropped too low to operate safely.
Your boiler has stopped working because there is not enough water pressure in the central heating system.
Your boiler is overheating because the water inside it is not moving around the system correctly.
Your boiler has failed to heat the water in your cylinder 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's internal computer has encountered an error that requires a manual restart, or it has been reset too many times in a short period.
Your boiler has stopped working because the fan that safely pushes waste gases out of the flue is not spinning at the correct speed or has failed.
Your boiler has stopped working because it cannot confirm that the fan is safely clearing waste gases from the system.
Your boiler has detected an issue with how the water is circulating or a sensor fault, causing the system to shut down for safety.
Your boiler has detected an issue with how it clears waste gases, preventing it from firing up safely.
Your boiler has detected that it is firing without enough water inside it, which causes it to overheat rapidly to prevent damage.
Your boiler has lost its electrical ground connection, causing the system to shut down safely to prevent an electrical fault.
Your boiler has switched itself off because the water inside the main heating unit has become dangerously hot.
Your boiler has stopped working because it cannot properly detect the temperature of the water returning from your radiators.
Your boiler has stopped working because it cannot correctly read the temperature of the water coming back into the system due to a faulty or disconnected sensor.
Your boiler has stopped working because it thinks the water returning to the unit is hotter than the water leaving it, which usually indicates a sensor error or a problem with water circulation.
Your boiler is repeatedly losing its flame during operation, which has caused the system to shut down for safety.
Your boiler's fan is not spinning at the correct speed to safely clear exhaust fumes, possibly due to a blockage, high winds, or a mechanical failure.
Your boiler has detected that water is flowing the wrong way or overheating internally, causing it to lock out for safety.
Your boiler has stopped working because water is not moving through the system or an internal sensor has lost its connection.
Your boiler has shut down because it is getting too hot inside, usually due to water not flowing through the system correctly or a faulty sensor.
Your boiler is simply acknowledging that the reset button has been pressed and is now attempting to restart its normal operation.
Your boiler has detected that there is not enough water in the system to operate safely, causing it to shut down to prevent damage.
Your boiler’s internal computer has suffered a critical failure or a communication timeout and can no longer control the heating process safely.
Your boiler is failing to start because its internal computer and gas control system are no longer talking to each other.
Your boiler’s internal control board has detected a configuration setting change that is preventing it from running correctly.
Your boiler's main control board has detected an internal configuration setting error, meaning the system may not know exactly how it should be operating.
Your boiler's main control board has detected a configuration setting error, likely caused by a component failure or an incorrect setting within the internal computer.
Your boiler is having trouble communicating with external controls like your thermostat or timer due to a wiring issue.
Your boiler is having trouble communicating with your thermostat or wireless control system.
Your boiler has lost its connection to the component that controls the fuel supply, meaning it cannot safely 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, usually due to a faulty internal sensor or a wiring problem.
Your boiler has stopped working because it can no longer accurately measure the temperature of the water moving through the system.
Your boiler has shut down because it is getting too hot too quickly, usually because the water isn't 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 exhaust gases, and it has shut down as a safety precaution.
Your boiler has shut down because it is getting too hot inside, often due to water not moving through the system or a safety sensor failing.
Your boiler has overheated or detected a circulation issue, causing it to shut down for safety to prevent damage.
Your boiler is unable to ignite its flame, meaning it cannot provide heating or hot water for your home.
Your boiler thinks a flame is burning when it shouldn't be, causing the system to lock out for safety reasons.
Your boiler's fan, which safely pushes exhaust gases out of your home, has stopped spinning or is broken, causing the system to shut down for safety.
Your boiler has detected a internal hardware failure within its gas control system and has shut down as a safety precaution.
Your boiler has stopped working because it cannot accurately measure the temperature of the water inside the system.
Your boiler has become too hot and has shut down as a safety precaution to prevent damage.
Your boiler has stopped because the water isn't moving through the pipes correctly, likely caused by trapped air or a blockage.
Your boiler's internal computer has developed a fault and can no longer control the heating process safely.
Your boiler is struggling to light because there might be trapped air in the system or a problem with the gas supply.
Your boiler is unable to communicate with its gas valve, meaning it cannot ignite safely to provide heating or hot water.
Your boiler has lost communication with its outdoor temperature sensor, which helps it adjust the heating based on the weather outside.
Your boiler has detected that water isn't moving through the system properly, so it has shut down to prevent overheating.
Your boiler has detected that water is still circulating or a sensor is stuck when it should be at rest, preventing it from starting safely.
Your boiler's electronic control board is struggling to communicate with the valve that controls the gas supply, meaning it cannot ignite safely.
Your boiler has lost its ability to accurately measure the temperature of the water used for your radiators, causing it to stop running for safety.
Your boiler has detected a problem with how it disposes of waste gases, which could be caused by a sensor fault or a blockage in the drainage or exhaust pipes.
Your boiler has detected a sensor failure that monitors the temperature of the water returning to the unit, causing the system to stop working for safety.
Your boiler is struggling to accurately measure the temperature of your hot water, which typically prevents the system from heating it safely.
Your boiler is not getting enough air to burn gas safely, which often means the external exhaust pipe is obstructed or there is an issue with the ventilation fan.
Your boiler is struggling to detect when you turn on your hot taps, which means your water may not get hot or could fluctuate in temperature.
Your boiler’s internal computer has lost its timing settings and needs to be professionally synchronised with the gas valve to operate safely.
Your boiler is unable to accurately measure the water pressure inside the system, which is preventing it from heating your home safely.
Your boiler's internal computer parts are having trouble talking to each other, meaning the system cannot receive the signals it needs to start up.
Your boiler has failed an internal safety check while trying to automatically adjust its flame, causing it to shut down to prevent inefficient or unsafe burning.
Your boiler's internal computer brain is struggling to keep time or communicate properly with its internal clock.
Your boiler is struggling to move water through the system properly, which is causing it to stop to prevent overheating.
Your boiler has become too hot and has automatically shut down to prevent damage or safety issues.
Your boiler has detected that there is too much water pressure in the system, which can prevent it from running safely.
Your boiler has stopped working because the water pressure in the central heating system has dropped too low.
Your boiler has stopped working because the water pressure is too low and needs to be topped up.
Your boiler is struggling to move hot water around the system, which is usually caused by a blockage or a pump that has stopped working.
Your boiler is repeatedly losing its flame during operation and has shut down as a safety precaution.
Your boiler is struggling to keep a steady flame lit 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 reached a temperature that is too high, often caused by a circulation problem or a blockage.
Your boiler is not receiving a steady gas supply or is struggling to light and maintain a flame.
Your boiler has failed to light several times in a row and has locked itself out for safety.
Your boiler has stopped working because it cannot detect a steady flow of gas or it has lost its flame during operation.
Your boiler has detected that the water temperature readings are inconsistent, suggesting the water isn't moving through the system correctly or a sensor is faulty.
Your boiler has stopped working because the internal fan, which safely removes waste gases, is not spinning correctly or cannot communicate with the main control board.
Your boiler has detected a problem with the fan that pushes exhaust gases out of the flue, causing the system to shut down for safety.
Your boiler has lost its connection to the hot water temperature sensor, which means the system cannot safely tell how hot the water is.
Your boiler is having trouble measuring its internal water pressure and has stopped working as a safety precaution.
Your boiler's electronic brains have developed a fault and can no longer communicate with the rest of the system.
Your boiler's internal computer brain is confused or malfunctioning, preventing the system from starting its normal cycle.
Your boiler has detected that water is not circulating correctly through the system before the burner ignites.
Your boiler is overheating because it doesn't have enough water circulating through it to safely carry the heat away.
Your boiler has detected that the electricity supply coming into your home is at the wrong frequency, causing the system to lock out for safety.
Your boiler is unable to heat your water because the sensor responsible for monitoring the temperature has developed a fault.
Your boiler thinks it sees a flame even though it hasn't finished its startup sequence yet, so it has shut down for safety.
Your boiler is not receiving enough electrical power to operate correctly, or it cannot detect the incoming voltage.
Your boiler has detected that the water pressure is too low to operate safely and is currently performing a check to see if it can recover.
Your boiler has lost its internal connection to the gas control system, meaning it cannot safely ignite 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 overheating or water is not moving through the system fast enough to stay at a safe temperature.
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 struggling to move water through the system, which is causing it to overheat and shut down for safety.
Your boiler is overheating because water isn't moving through the system quickly enough when heating your water.
Your boiler's internal computer brain hasn't been programmed correctly or has forgotten its setup settings, meaning it doesn't know how to run properly.
Your boiler's control board is currently confused by its own internal configuration settings and cannot tell the system how to operate.
Your boiler's computer brain has become temporarily confused by its internal settings and cannot operate correctly.
Your boiler has detected low water pressure, which means there is not enough water in the system to operate safely.
Your boiler is having trouble 'talking' to its internal temperature sensors, which is causing it to stop running for safety.
Your boiler's main internal computer has lost communication with its control panel, meaning it can no longer send or receive instructions to heat your home.
Your boiler has lost its flame while it was running, meaning it has temporarily stopped working to ensure your safety.
Your boiler has lost power completely and and the control panel is unresponsive.
Your boiler has tried to light several times but has failed to detect a flame, causing it to shut down for safety.
Your boiler has detected an internal electrical communication problem that is preventing it from firing up.
BoilerFaultCodes