BoilerFaultCodesThe 6 most common faults
Your boiler is failing to detect a flame correctly during startup, causing it to stop for safety until you manually reset it.
Check that your gas pre-payment meter (if applicable) has creditEnsure other gas appliances like your hob are working to confirm gas supplyPress the reset button once to see if the fault was a temporary glitch
Your boiler appears to have no electrical power at all, meaning the screen and lights are completely blank.
Check if the boiler's power switch is turned onCheck your home's main fuse box (consumer unit) for a tripped circuit breakerCheck the fuse in the spurred power socket next to the boiler
Your boiler has shut down for safety because it either failed to light, sensed it was getting too hot, or detected an issue with how it clears waste gases.
Check that your gas pre-payment meter (if applicable) has credit.Ensure any external gas isolation valves are fully open.Press and release the reset button on the front control panel to see if the boiler restarts.
Your boiler is failing to recognise that the flame has lit, causing it to repeatedly try to spark before shutting down for safety.
Full guide for Lock---out signal lamp redYour boiler's internal computer has suffered a critical failure and can no longer control the heating or hot water functions.
Full guide for All Lamps ONYour boiler is currently switched off but is monitoring the temperature to prevent the internal pipes from freezing.
Turn the main control knob from the 'O' (Off) position to either 'Summer' or 'Winter' mode to restore normal heating and hot water.
on the Biasi Garda M90f
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