BoilerFaultCodesGlow-worm 32 Fault Code
The Glow-worm 32 fault code means: your boiler has detected a fault with the sensor that monitors water temperature returning from your radiators, preventing the system from heating up properly.. It appears on 1 Glow-worm model in our database.
Technical description: The heating return thermistor is short circuited.
What causes the Glow-worm 32 fault?
This fault occurs when the sensor responsible for measuring the temperature of the water coming back from your radiators fails or develops an electrical fault. The most common reason is that the internal components of the sensor have degraded over time or moisture has compromised the electrical connection, causing it to send a faulty signal to the main control board.
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 32 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm 32 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