BoilerFaultCodesThe 6 most common faults
Your boiler has detected that it is getting too hot or the water isn't moving through the system correctly, causing it to shut down for safety.
Check that all radiator valves are fully openEnsure the system pressure is at the correct level (usually 1.0 to 1.5 bar)Check for any visible leaks around the boiler and pipework
Your boiler has become too hot and has automatically shut down for safety purposes.
Ensure all radiator valves are fully open and there are no obstructions to water flow.Wait for the boiler to cool down completely.Locate the manual reset button (usually tucked under the bottom of the boiler) and press it firmly to restart the unit.
Your boiler has tried to light itself several times but cannot establish a flame, meaning your heating and hot water will not work.
Check if other gas appliances, like a hob, are working to ensure gas is reaching the propertyCheck that your gas meter has credit if you use a pre-payment meterSwitch the boiler off and on again at the fused spur switch to attempt a reset
Your boiler's internal safety system has detected that the fan responsible for clearing exhaust gases is not working correctly, preventing the boiler from starting.
Full guide for 4 red flashesYour boiler's computer has lost its settings or is failing to communicate with its memory chip, causing the system to stop working.
Full guide for 5 red flashesYour boiler has detected a general internal fault that is preventing it from firing up safely, often caused by a component failing to communicate properly.
Full guide for 6 red flasheson the Baxi Profile Prima
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