BoilerFaultCodesThe 6 most common faults
01
F37 High DIY-safe
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
What to try first
Locate the filling loop, which is usually a metal braided hose underneath the boiler.Open the small valve or tap attached to the loop slowly, listening for water entering the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically 1.0 to 1.5 bar).Close the valve or tap tightly and check that the fault code has cleared.
02
F43 High Engineer
Your boiler has detected that the heat exchanger is getting too hot, likely due to a lack of water flow, triggered to prevent potential damage to the internal components.
Full guide for F4303
A01 High Engineer
Your boiler is failing to light the flame, which means it cannot produce any hot water or heating.
Full guide for A0104
A06 High Engineer
Your boiler is failing to light the internal burner, so it has safely shut itself down to prevent a gas build-up.
Full guide for A0605
F07 High Engineer
Your boiler has detected an issue with the temperature sensors, meaning it cannot accurately measure how hot the water is and has stopped working as a safety precaution.
Full guide for F0706
F14 High Engineer
Your boiler has detected that the exhaust gases leaving the system are getting too hot, so it has shut itself down to prevent damage.
Full guide for F14on the Ferroli Bluehelix Pro RRT
Filling loopPressure sensor (transducer)Expansion vesselCentral heating pumpSystem filterFlow sensor
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
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