BoilerFaultCodesThe 6 most common faults
Your boiler is trying to light but cannot successfully create or detect a flame, causing it to shut down for safety.
Check that your gas supply is turned on at the meterCheck if other gas appliances (like a hob) are workingPress the reset button to attempt a restart
Your boiler has lost power completely, meaning it will not turn on or provide any heating or hot water.
Check if other appliances in your home have powerCheck your main property fuse box to see if a circuit has trippedEnsure the boiler's power switch on the wall (fused spur) is turned on
Your boiler has detected that the water pressure is too low, which prevents it from heating up safely.
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the small valves on the filling loop until you hear water moving.Watch the pressure gauge and close the valves once the needle reaches between 1 and 1.5 bar.
Your boiler has entered a safety lockout mode and stopped working because it failed to light or stay lit through several attempts.
Check that your gas supply is active and other gas appliances are workingLocate the reset button or selector switch on the control panelTurn the selector to the 'R' (Reset) position for 2 seconds and then back to the on position
Your boiler has switched itself off because it has reached an unsafe temperature, likely due to a blockage or a failure in how the water is moving through the system.
Check that all radiator valves are fully openEnsure the boiler pressure is between 1 and 1.5 bar on the gaugeTry to reset the boiler once it has cooled down for 30 minutes
Your boiler has too much water inside it, causing the pressure to rise to an unsafe level.
Check that the filling loop valves under the boiler are tightly closed.Locate a radiator and use a bleed key to release water into a container until the pressure gauge falls to 1.5 bar.If the pressure continues to rise on its own, turn off the cold water mains and call a professional.
on the Biasi Gaia
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 Biasi 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