17 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: ecoTEC
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
Tap any card for details
Your boiler has attempted to start several times but has failed to ignite the flame, so it has stopped working for your safety.
Your boiler is failing to stay lit after the initial ignition, meaning it cannot provide heat or hot water and has shut down for safety.
Your boiler has detected that it is getting too hot and has automatically switched itself off to prevent any damage or safety hazards.
Your boiler has lost the ability to measure the temperature of the water used for your radiators, so it has shut down as a precaution to prevent overheating.
Your boiler is struggling to accurately measure the temperature of the water returning to it, so it has stopped working as a safety precaution until the faulty sensor is corrected.
Your boiler's computer is struggling to communicate with internal sensors, meaning it cannot safely start the heating or hot water.
Your boiler's electronic control panel is failing to communicate with the main internal computer, which disables the system's ability to operate.
Your boiler's electronic brain has developed a internal communication error, meaning it can no longer safely operate the system.
Your boiler has detected that the internal water temperature is dangerously high and it has automatically shut down to prevent damage.
Your boiler is struggling to confirm that the flame has properly extinguished after it has finished running, which is a safety lockout to prevent potential gas build-up.
Your boiler is not receiving enough electrical voltage to operate safely and effectively.
Your boiler's electronic display or control panel is having communication trouble, which prevents it from properly managing your heating and hot water.
Your boiler has lost the connection to the sensor that monitors the temperature of the water circulating through your radiators, causing it to stop heating.
Your boiler's computer components are not talking to each other correctly due to a software mismatch, which has caused the system to stop working to ensure safety.
Your boiler has detected that the water returning to it is much too hot, suggesting it cannot circulate heat properly through your radiators.
Your boiler has detected that the water inside is heating up far too quickly, which usually suggests a problem with the internal sensors or a blockage preventing water from flowing properly.
Your boiler has detected that the water is heating up significantly faster than it is circulating through your radiators, which usually signals a blockage or a pump failure.
BoilerFaultCodes