25 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is failing to light because it cannot detect or supply the correct amount of gas for the burner to operate safely.
Your boiler has detected that a seal around the internal fan unit has failed or is leaking, which prevents the system from safely venting gases.
Your boiler has stopped working because a sensor that monitors water temperature is not sending the correct signal to the control system.
Your boiler has failed to light the flame properly, meaning it cannot produce heat or hot water because the ignition system is not functioning.
Your boiler is failing to ignite correctly because the gas flow mechanism is restricted or faulty, preventing it from heating your home.
Your boiler has failed to ignite because the gas supply reaching the burner is not at the correct pressure or is being blocked, preventing it from heating your home.
Your boiler is failing to ignite or stay lit because the internal gas distribution system is blocked or malfunctioning.
Your boiler's central control computer is experiencing an internal error, which has caused the system to shut down for your safety.
Your boiler has lost the ability to send electrical signals between its internal parts, meaning it cannot communicate correctly to start heating.
Your boiler is failing to ignite because it cannot detect a flame, likely due to a faulty or dirty sensor that helps start the fire.
Your boiler has stopped working because it cannot confirm that the internal fan is moving air correctly, which is a vital safety check to ensure exhaust gases are cleared properly.
Your boiler has detected an internal communication error with its main control unit, meaning it is unable to safely manage its heating operations.
Your boiler is having trouble communicating with its internal temperature controls, which means it cannot accurately sense how hot the water needs to be and has safely shut down to prevent overheating.
Your boiler's fan, which is responsible for safely venting exhaust gases outside, has stopped working correctly, causing the system to shut down for safety reasons.
Your boiler's air extraction system is not operating correctly, which prevents the unit from starting the ignition process to keep you safe.
Your boiler has detected that exhaust gases are not escaping correctly through the flue, which is a safety mechanism to prevent dangerous fumes from entering your home.
Your boiler has detected that dangerous exhaust gases are not escaping correctly through the flue, so it has shut down for your protection.
Your boiler's burner is failing to ignite or stay lit, meaning your heating and hot water will not work until a professional resolves the issue.
Your boiler is failing to light because it cannot detect or maintain an active flame, causing the system to shut down for safety.
Your boiler is failing to detect the gas flow required to ignite, meaning it cannot produce heat or hot water because the internal gas supply component is not responding correctly.
Your boiler has detected an issue with its internal airflow system, which is preventing it from safely starting up to provide heat or hot water.
Your boiler has detected an issue with the sensor that confirms the internal fan is moving air correctly, so it has shut down to prevent unsafe operation.
Your boiler is failing to detect the airflow needed for safe operation, so it has automatically shut down to prevent it from running incorrectly.
Your boiler has stopped working because it cannot safely ignite or maintain a flame, meaning you currently have no heating or hot water.
Your boiler has stopped working because it cannot light the internal flame, which means you currently have no heating or hot water.
BoilerFaultCodes