BoilerFaultCodesGlow-worm Fan Hunt Fault Code
Also written as FANHUNT — same fault.
The Glow-worm Fan Hunt fault code means: your boiler is struggling to start up properly because the main internal computer is failing to control the fan correctly.. It appears on 2 Glow-worm models in our database.
Technical description: Faulty printed circuit board
What causes the Glow-worm Fan Hunt fault?
This fault occurs when the boiler's main control board loses the ability to communicate properly with the fan motor, leading to erratic speeds or 'hunting' for the correct setting. The most common reason is that the electrical components on the circuit board have degraded over time, meaning it can no longer send a steady signal to keep the fan running safely.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Glow-worm models that show the Fan Hunt fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm Fan Hunt 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