BoilerFaultCodesThe 6 most common faults
Your boiler has failed to light the gas flame, meaning it has shut itself down for safety and cannot provide heating or hot water.
Check if your gas supply is active by testing another gas appliance like a hob.Perform a reset by turning the control knob to 'R' for five seconds and then back to the on position.Verify that your condensate pipe (the plastic pipe leading outside) isn't frozen if it is currently winter.
Your boiler has switched itself off because it has detected that it is getting too hot inside.
Check that all radiator valves are open to ensure water can flow.Ensure there are no blockages in the system by checking for trapped air in radiators.Press the Reset button on the boiler control panel once to see if it restarts.
Your boiler has detected that there is not enough water or water pressure to operate safely, causing it to shut down.
Locate the pressure gauge on the front of your boiler.If the needle is below 1, find the filling loop valves underneath the boiler.Slowly open both valves to top up the system until the gauge reaches between 1 and 1.5 bar, then close them tightly.
Your boiler is unable to move water around the system properly, which has caused it to shut down to prevent overheating.
Check that your central heating valves (under the boiler) are fully openEnsure all radiator valves are turned on and not closedCheck if the boiler pressure gauge is between 1.0 and 1.5 barGently bleed your radiators to remove any trapped air pockets
Your boiler is failing to recognise that the flame has lit correctly, causing the system to shut down for safety.
Check if other gas appliances in your home, like a gas hob, are working to ensure gas is reaching the propertyCheck that your prepaid gas meter has credit, if applicablePress the Reset button on the boiler control panel and hold for five seconds
Your boiler has shut down because the waste water pipe that carries away condensation is blocked or frozen, causing water to back up into the unit.
Locate the plastic white pipe exiting the wall outside your property.If the weather is freezing, pour warm (not boiling) water over the external pipe to melt any ice blockages.Check that the end of the pipe is not submerged in water or blocked by debris.Reset the boiler using the control knob to see if the error clears.
on the Biasi Activa
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