BoilerFaultCodesThe 4 most common faults
01
LED5 flashing High DIY-safe
Your boiler has switched itself off because the water pressure in your heating system has dropped too low to operate safely.
What to try first
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Open the filling loop valves slowly until you hear water flowing and watch the pressure gauge.Close both valves tightly once the pressure gauge reaches between 1 and 1.5 bar.
02
LED2 on High DIY-safe
Your boiler has entered a safety lockout mode because it either failed to light properly or it has detected that the system is getting too hot.
What to try first
Check that your gas supply is turned on and you have credit on your meter.Locate the selector switch and turn it to the 'R' (Reset) position for several seconds, then back to 'On'.Ensure your radiator valves are open and the system pressure is between 1 and 1.5 bar.
03
E03 High Engineer
Your boiler has stopped working because it cannot safely confirm that the fan is moving air and exhaust gases correctly through the system.
Full guide for E0304
LED 2 High Engineer
Your boiler has detected an internal fault and has shut down as a safety precaution, meaning you currently have no heating or hot water.
Full guide for LED 2on the Ferroli Modena F
Filling loopExpansion vessel re-pressurisationPressure sensorIgnition ElectrodeOverheat ThermostatGas Valve
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