BoilerFaultCodesGlow-worm F02 Fault Code
The Glow-worm F02 fault code means: your boiler has stopped working because it cannot safely expel waste gases or verify that the internal fan is moving air correctly.. It appears on 1 Glow-worm model in our database.
Technical description: Air flow fault - Air pressure switch / Fan fault
What causes the Glow-worm F02 fault?
This fault occurs when the boiler's internal safety sensors fail to detect the necessary movement of air required to safely ignite the burner. The most common reason is a malfunctioning fan that cannot spin fast enough or a blockage in the small tubes that measure air pressure, which prevents the boiler from confirming it is safe to operate.
This fault can sometimes occur during periods of high winds, as strong gusts can cause back-pressure in the flue that disrupts the sensitive air pressure readings.
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 F02 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F02 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