BoilerFaultCodesGlow-worm F61 Fault Code
The Glow-worm F61 fault code means: your boiler has detected an internal communication failure between the main control board and the gas valve, meaning it cannot safely light the flame.. It appears on 9 Glow-worm models in our database.
Technical description: Main PCB gas valve control fault
What causes the Glow-worm F61 fault?
This fault occurs when the boiler's main computer loses the ability to send or receive signals from the gas valve, which is the component that controls the flow of fuel. The most common reason is an electronic failure within the circuit board itself or a loose connection in the internal wiring. Because the boiler cannot confirm it can safely control the gas supply, it shuts down as a safety precaution.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Glow-worm models that show the F61 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F61 fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026