33 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Icos
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Your boiler's internal memory card has failed to communicate, meaning the control system no longer recognizes which model it is supposed to be operating.
Your boiler's internal memory chip has developed a communication error or has failed, meaning the main control board cannot identify which model it is operating.
Your boiler has detected that the water pressure is too low for it to operate safely, which is usually a simple matter of the system needing a top-up.
Your boiler has failed to stay lit, which means it has stopped providing heating and hot water for safety reasons.
Your boiler has started to light but the flame has gone out, meaning the system has shut down for safety and cannot provide heat or hot water.
Your boiler has detected an issue with the fan that safely pushes waste gases out of your home, causing the system to shut down for safety.
Your boiler has detected an issue with the sensor that monitors the temperature of the water leaving the unit, causing it to shut down to prevent overheating.
Your boiler has lost its ability to accurately measure the temperature of the water returning to the unit, causing it to shut down to prevent damage.
Your boiler has lost connection with its outdoor thermometer, meaning it cannot automatically adjust your heating based on the weather outside.
Your boiler has stopped working because the electrical supply from the power grid is currently too weak to power the appliance safely.
Your boiler's internal computer brain hasn't been set up correctly to tell the unit how to operate, so it has shut down for safety.
Your boiler's internal computer has either lost its memory or developed a technical fault, preventing the unit from starting up.
Your boiler has detected that the water is flowing in the wrong direction through the pipes, or there is an issue with the temperature sensors.
Your boiler has stopped working because water is not moving through the system correctly, which is often caused by a lack of water pressure or a blockage.
Your boiler has detected that the temperature sensors on the main pipes are showing unusual readings, often because the water flow is not moving in the direction the system expects.
Your boiler has detected that the water temperature readings are backwards, which usually means a sensor has come loose or is faulty.
Your boiler has detected that water is getting too hot too quickly, which usually means the water isn't flowing through the system properly.
Your boiler has stopped working because it failed to light the flame after several attempts, typically due to a temporary interruption in the gas supply.
Your boiler has shut down because it has become too hot or water is not circulating through the system correctly.
Your boiler has tried to light several times but failed, so it has shut itself down for safety.
Your boiler has detected that water is getting too hot too quickly or a temperature sensor has failed, causing the system to shut down for safety.
Your boiler has been manually reset too many times in a short window, causing the system to lock itself out for safety.
Your boiler has detected a problem with the sensor that monitors the temperature of the water returning to the unit, causing it to shut down for safety.
Your boiler thinks a flame is present when it shouldn't be, causing the system to shut down safely to prevent a gas hazard.
Your boiler has experienced a temporary electronic glitch and simply needs to be restarted to clear its memory.
Your boiler is not receiving enough electrical power to operate properly and has shut down for safety.
Your boiler has stopped working because there is not enough water in the system to operate safely.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Your boiler has stopped working because the internal pump that moves water around your pipes is stuck or jammed.
Your boiler has switched itself off because it got too hot and needs to be safely cooled down and restarted.
Your boiler has been manually reset too many times in a short window and has temporarily locked itself out as a safety precaution.
Your boiler is trying to fire up too many times in a short window because it keeps failing to stay alight.
Your boiler has stopped working because the water pressure inside the system is too low to operate safely.
BoilerFaultCodes