BoilerFaultCodesThe 5 most common faults
01
A02 High Engineer
Your boiler thinks a flame is burning even when it’s supposed to be turned off, which causes it to shut down as a safety precaution.
Full guide for A0202
F10 High Engineer
Your boiler has stopped working because it is unable to accurately measure the temperature of the water flowing out of it.
Full guide for F1003
A15 High Engineer
Your boiler is struggling to clear exhaust gases because it cannot confirm that the internal fan is moving air properly, so it has shut down for safety.
Full guide for A1504
F50 High Engineer
Your boiler's internal computer has developed an electrical fault and is unable to communicate with its sensors properly.
Full guide for F5005
F51 High Engineer
Your boiler's internal computer has developed a critical electronic fault and can no longer control the heating system safely.
Full guide for F51on the Ferroli i29
Ionisation ElectrodeFlame Sensing CableMain PCBNTC delivery sensorWiring harnessAir pressure switch
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
Boiler cover options
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.