BoilerFaultCodesThe 6 most common faults
Your boiler has detected that it is getting too hot or the water isn't moving through the system properly, causing it to shut down for safety.
Check that your radiator valves are openEnsure the system pressure is between 1 and 1.5 bar on the gaugeTry resetting the boiler using the dial or reset button
Your boiler has become too hot and has automatically shut itself down to prevent damage.
Turn off the boiler at the main electrical switch and wait 15 minutes for it to cool down.Check that your radiator valves are open and that there is enough water pressure in the system.Press the reset button firmly; if the red light persists or recurs, you must call a professional.
Your boiler has tried to light several times but cannot start up, meaning you currently have no heating or hot water.
Check that your gas pre-pay meter is in creditEnsure any gas isolation valves are turned to the 'on' positionPress and hold the reset button for five seconds to restart the ignition sequence
Your boiler has encountered a general electronic fault and needs to be reset to try and clear the error.
Locate the reset button or selector switch on the front control panelTurn the selector to the reset position and hold for 5 secondsRelease the switch and wait for the boiler to attempt a restart
Your boiler has detected that the internal fan, which clears waste gases out of the flue, is not spinning correctly or has lost power.
Full guide for 4 red flashesYour boiler's internal memory unit has developed a communication fault, meaning the control board no longer knows how to operate the system safely.
Full guide for 5 red flasheson the Baxi Netaheat
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