BoilerFaultCodesThe 6 most common faults
Your boiler has detected a problem with how it releases exhaust gases or a blockage in the drainage system, causing it to shut down for safety.
Check the external flue pipe outside your home for obstructions like bird nests or debris.Inspect the white plastic condensate pipe outside for signs of freezing or blockages.If the condensate pipe is frozen, gently pour warm (not boiling) water over it to thaw it.Reset the boiler once to see if the fault clears.
Your boiler has likely overheated, causing a safety sensor to shut it down to prevent damage.
Allow the boiler to cool down for 20 to 30 minutesCheck that your radiator valves are open and not blockedPress and hold the 'R' or Reset button for five seconds
Your boiler has stopped working because the water pressure inside the system is too low.
Locate the filling loop (the flexible silver hose) underneath or near the boiler.Slowly open the valve or valves on the loop until you hear water flowing.Watch the pressure gauge and close the valves once the needle reaches between 1.0 and 1.5 bar.
Your boiler has detected that water is not moving around the system properly, which is causing it to overheat and shut down for safety.
Check that your silver radiator valves (TRVs) are turned up and not all closed at once.Inspect your system pressure gauge and top it up to 1.5 bar if it is too low.Gently bleed your radiators to remove any trapped air pockets.
Your boiler has failed to light because it either cannot get enough gas or cannot detect a flame.
Check if other gas appliances like your hob are working to confirm your gas supply is active.If you have a prepaid meter, ensure you have credit.Hold the reset button for five seconds to see if the boiler restarts.If it is freezing outside, check that your white condensate pipe is not frozen.
Your boiler has sensed that water is not moving through the internal pipes quickly enough before the burner starts, often caused by a blockage or air trapped in the system.
Check that all radiator valves are fully openEnsure the boiler pressure is between 1 and 1.5 bar on the gaugeGently bleed your radiators to remove any trapped airSwitch the boiler off and on again to reset the system
on the Baxi EP
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