d.93 High

Glow-worm d.93 Fault Code

Also written as D93 — same fault.

The Glow-worm d.93 fault code means: your boiler is currently in a setup mode and does not know which specific model configuration it should be running, meaning it cannot heat your home or water until this is programmed.. It appears on 6 Glow-worm models 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: Setting the product code
Typical repair cost £90-180 (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 d.93 fault code

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

Source

Glow-worm d.93 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