BoilerFaultCodesGlow-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 11 Glow-worm models in our database.
Technical description: Setting the product code
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.
- Compact Repair: £120-250
- Easicom 24 Repair: £150-300
- Easicom 28 Repair: £150-300
- Energy7 Combi Repair: £90-180
- Flexicom 24c / 28c Repair: £120-250
- MicraCom Repair: £100-200
- Sustain 12s Repair: £90-150
- Sustain 15s Repair: £90-150
- Sustain 18s Repair: £90-150
- Ultimate 3 25R Repair: £100-200
- Ultimate3 Combi Repair: £100-£200
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 31 August 2026