10 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Promax SL
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 stopped working because it cannot light the internal flame, which means you currently have no heating or hot water.
Your boiler is operating exactly as it should and has successfully lit the flames to provide you with heat and hot water.
Your boiler has switched itself off because it has detected an dangerous buildup of heat or a potential issue with the discharge of exhaust gases.
Your boiler has detected a blockage in the chimney or flue pipe, which could allow dangerous exhaust gases to enter your home.
Your boiler has switched itself off because it became too hot, acting as a safety precaution to prevent damage.
Your boiler has detected that fumes are not escaping properly through the flue, so it has shut itself down automatically to keep you safe from harmful exhaust gases.
Your boiler has automatically shut down for safety because it has detected that it is getting too hot or that harmful exhaust gases are not escaping correctly through the flue.
Your boiler has shut down because a safety sensor has detected that dangerous exhaust fumes are not escaping through the chimney correctly.
Your boiler has become too hot and has automatically shut itself down to prevent damage or safety issues.
Your boiler has detected an internal electrical or safety fault and has stopped running to prevent damage.
BoilerFaultCodes