BoilerFaultCodesThe 6 most common faults
Your boiler has detected a problem with how it disposes of waste gases or a blocked drainage pipe, causing it to shut down for safety.
Check the white plastic condensate pipe outside for signs of freezing or blockages.If the external pipe is frozen, gently pour warm (not boiling) water over it to thaw the ice.Check the flue terminal on your outside wall for any obvious obstructions like bird nests or debris.Reset the boiler by turning the selector switch to the 'R' position for five seconds.
Your boiler has overheated, prompting a safety sensor to shut it down to prevent damage.
Check that your radiator valves are open to allow water to flowEnsure your system pressure is topped up to between 1 and 1.5 barTurn the selector knob to the 'Reset' position and hold for five seconds
Your boiler has stopped working because the water pressure is too low for the system to run safely.
Locate the filling loop (usually two blue levers or a braided hose under the boiler).Slowly open the valve(s) and watch the pressure gauge increase.Close the valves tightly once the pressure reaches between 1.0 and 1.5 bar.
Your boiler has tried to ignite but failed, which means the gas isn't reaching the burner or the flame isn't being detected.
Check that your gas meter has credit and the isolation valve is open.Try to reset the boiler by turning the selector switch to 'R' for five seconds.If it is freezing outside, check if your white plastic condensate pipe is frozen and thaw it with warm water.
Your boiler has got too hot and has shut itself down as a safety precaution to prevent damage.
Switch the boiler off and allow it to cool down completely.Check all radiator valves are open and bleed your radiators to remove trapped air.Check the boiler pressure gauge and top it up to 1.5 bar if it is too low.Press the Reset button for 5 seconds to restart the system.
Your boiler has stopped working because the water pressure is too low, often caused by a small leak or air in the radiators.
Locate the filling loop (the silver braided hose) underneath your boiler.Slowly open the one or two taps/levers on the filling loop until you hear water moving.Watch the pressure gauge until it reaches between 1 and 1.5 bar, then close the taps tightly.
on the Baxi Assure
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