8.1 High

Glow-worm 8.1 Fault Code

Also written as 81 — same fault.

The Glow-worm 8.1 fault code means: your boiler's small starter flame is cutting out unexpectedly, which stops the main heater from running.. It appears on 1 Glow-worm model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Pilot Goes Out after a Period of Remaining Alight
Typical repair cost £120-250 (including labour)

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 8.1 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Glow-worm 8.1 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 7 July 2026