Home/Boiler Fault Codes/Glow-worm F13
GLOW-WORM FAULT CODE
Glow-worm F13
Points to a problem with the main PCB or its wiring, or in some cases a fault with a temperature sensor and its wiring.
WHAT F13 TYPICALLY INDICATES
Points to a problem with the main PCB or its wiring, or in some cases a fault with a temperature sensor and its wiring.
WHAT TO DO
This is not a DIY fix — it requires a Gas Safe registered engineer to diagnose and repair safely.
A NOTE ON GAS SAFE REGISTRATION
Any work on the gas side of a boiler in the UK legally requires a Gas Safe registered engineer, it isn't optional. Our engineers are fully Gas Safe registered, and you're always welcome to ask to see ID on the day. This page is general information about what a fault code typically indicates; it is not a substitute for an engineer diagnosing your specific boiler.
Seeing Glow-worm F13 on your boiler?
Tell us the code and your postcode. A fully Gas Safe registered engineer will diagnose the actual cause before quoting a fix.
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