BoilerFaultCodesGlow-worm F2 Fault Code
The Glow-worm F2 fault code means: your boiler has likely experienced an internal electrical fault or a component failure that has caused a safety fuse on the main control board to blow.. It appears on 6 Glow-worm models in our database.
Technical description: Fuse Type (F1A). Before using the fault finding chart ensure all wiring is correct and in good condition, the pump is not faulty and check the PCB fuse F2.
What causes the Glow-worm F2 fault?
This fault occurs when an electrical surge or a component failure causes a safety fuse on the main control board to blow, cutting power to prevent further damage. The most common reason is a seizing water pump that is drawing too much current or a short-circuit within the boiler's internal wiring. As a result, the boiler shuts down completely to protect its sensitive electronic parts.
This fault is more common in the autumn when heating systems are turned on for the first time after summer, as pumps are more likely to seize after long periods of inactivity.
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 F2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F2 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 Compact (2006-2011) manual (PDF)
- Glow-worm Glow-worm Micron 100FF 120FF manual (PDF)
- Glow-worm Jaguar Combi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026