BoilerFaultCodesGlow-worm F06 Fault Code
The Glow-worm F06 fault code means: your boiler has detected a problem with the sensor that monitors the temperature of the water leaving the unit to heat your radiators.. It appears on 1 Glow-worm model in our database.
Technical description: Central heating flow NTC fault
What causes the Glow-worm F06 fault?
This fault occurs when the boiler's control board loses communication with the sensor that monitors the temperature of the water sent to your radiators. The most common reason is that the sensor itself has worn out and failed, though it can also be caused by loose or damaged internal wiring connecting the sensor to the main computer.
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 F06 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F06 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