BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the external filling loop, which is usually a flexible silver hose connected to two valves beneath the boiler.Open the valves slowly to allow cold mains water into the system while watching the pressure gauge on the front of the boiler.Stop filling once the needle reaches the green zone, typically between 1.0 and 1.5 bar, then securely close both valves.
Your boiler has stopped working because the water pressure inside the heating system has dropped too low to operate safely.
Locate the external filling loop, which is usually a small silver braided hose connecting two pipes under the boilerOpen the valves at both ends of the hose to allow mains water into the heating systemWatch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically between 1.0 and 1.5 bar)Close both valves tightly and remove or disconnect the filling loop if required
Your boiler has lost the ability to accurately measure the temperature of the water circulating to your radiators, so it has shut down as a precaution.
Full guide for E20Your boiler is struggling to clear exhaust gases safely and has turned itself off to prevent a potential hazard.
Full guide for E28Your boiler is currently unable to sense the temperature of your hot water properly, which means it has stopped heating your water to prevent it from getting too hot.
Full guide for E50Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Full guide for E110on the Baxi Duo-tec Combi ErP
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Baxi shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue