BoilerFaultCodesGlow-worm F11 Fault Code
The Glow-worm F11 fault code means: your boiler's internal computer parts are struggling to talk to each other, preventing the system from starting up.. It appears on 4 Glow-worm models in our database.
Technical description: Electronic control board (PCB) communication error.
What causes the Glow-worm F11 fault?
This fault occurs when the main electronic brain of your boiler loses its connection with the internal components it needs to control. It is usually caused by a physical break in the wiring or a burnout of the circuitry on the printed circuit board itself, preventing the boiler from receiving the signal to start heating.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Glow-worm models that show the F11 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F11 fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
- Glow-worm CXi manual (PDF)
- Glow-worm Easicom 24 manual (PDF)
- Glow-worm Flexicom 24c / 28c manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026