BoilerFaultCodesThe 6 most common faults
Your boiler has failed to ignite or has lost its flame, causing the system to lock out for safety.
Check if other gas appliances, like a cooker, are working to confirm gas supplyEnsure the condensate pipe (outside) is not frozen if it is winterTurn the selector switch to the 'Reset' position, wait five seconds, then turn it back to the 'On' position
Your boiler has likely overheated, causing the safety system to shut it down to prevent damage.
Locate the reset button on the control panel.Press and hold the reset button for a few seconds until the fault light clears.Ensure your radiator valves are open and that the system pressure is between 1 and 1.5 bar.
Your boiler has detected low water pressure in the system, which means there isn't enough water to circulate and provide heating or hot water safely.
Locate the filling loop (usually two small valves connected by a silver braided hose) underneath the boiler.Slowly open both valves and watch the pressure gauge needle rise.Close both valves tightly once the pressure gauge reaches between 1.0 and 1.5 bar.
Your boiler has likely detected a circulation or overheating issue, meaning water isn't moving through the system correctly to keep it cool.
Check that your system pressure is between 1.0 and 1.5 bar on the pressure gaugeEnsure all radiator valves are fully open, including those on towel railsPress and hold the Reset button for 2-5 seconds to see if the fault clears
Your boiler has detected that the water inside has become far too hot, causing the system to shut down safely to prevent damage.
Wait at least 30 minutes for the boiler to cool down naturally.Locate the manual reset button on the control panel.Press and hold the reset button for a few seconds to clear the lockout.
Your boiler has likely detected an overheating issue which has caused it to shut down to prevent damage.
Check that all radiator valves are fully openEnsure the system pressure is between 1.0 and 1.5 barPress the reset button on the front control panelAllow the boiler to cool down for 20 minutes before restarting
on the Biasi M90E 24S
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