BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside your heating system has dropped too low to operate safely.
Locate the external filling loop (a flexible silver hose connecting two pipes near the boiler).Open the valves on both ends of the hose to allow water into the system until the gauge reads between 1.0 and 1.5 bar.Close both valves tightly and ensure no water is leaking from the hose connections.
Your boiler is not starting because it is failing to ignite, meaning it cannot produce heat or hot water.
Check that your gas meter is turned on and other gas appliances like a hob are workingEnsure the gas isolation valve located near the boiler is in the open positionPress and release the reset button on the boiler control panel once
Your boiler is not firing up because it cannot detect a flame, which means you currently have no heating or hot water.
Check that your gas supply is turned on at the meter and the boiler isolation valveEnsure other gas appliances like your cooker are working to rule out a gas supply cut-offPress and hold the Reset button on the front of the boiler for a few seconds
Your boiler is failing to ignite the flame needed to warm your water or heating system.
Check that your gas supply is definitely on by verifying other gas appliances like a hob are workingEnsure the gas isolation valve near the boiler is turned to the fully open positionPress and release the reset button on the boiler control panel once
Your boiler is not firing up because it cannot detect a flame, which means it currently cannot provide heating or hot water.
Check that your gas supply is turned on at the meterEnsure the gas isolation valve near the boiler is set to the open positionPress the reset button once to try and restart the boiler
Your boiler is currently unable to start because it is not receiving or burning gas successfully.
Check that your gas supply is definitely on by testing another appliance like a gas hobLocate the gas isolation valve near the boiler and ensure the handle is in the 'on' positionPress the reset button on your boiler's control panel and wait to see if it ignites
on the Ferroli Optimax 25 C
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 Ferroli 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