BoilerFaultCodesGlow-worm F72 Fault Code
The Glow-worm F72 fault code means: your boiler is struggling to accurately measure the water temperature, causing it to shut down to prevent overheating.. It appears on 8 Glow-worm models in our database.
Technical description: Flow and/or Return thermistor fault
What causes the Glow-worm F72 fault?
This fault occurs when the boiler's control board receives conflicting or incorrect temperature signals from the sensors on the main pipes. It usually happens because these sensors have drifted out of their correct calibration or the wiring connecting them has degraded. As a safety precaution, the boiler shuts down because it can no longer accurately monitor if the water is getting too hot.
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 F72 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm F72 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 Betacom2 28 manual (PDF)
- Glow-worm Easicom 28 manual (PDF)
- Glow-worm Ultracom 2 35cxi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026