BoilerFaultCodesGlow-worm F.70 Fault Code
Also written as F70 — same fault.
The Glow-worm F.70 fault code means: the boiler's internal computer has lost its identification settings, usually because a new control board was fitted without being programmed correctly for your specific unit.. It appears on 19 Glow-worm models in our database.
Technical description: Invalid product code (DSN). Display and PCB replaced at same time and Device Specific Number not reset, wrong or missing output range coding resistance
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 F.70 fault code
Click a model for the full fault code list and model-specific repair notes.
- 30cxi Repair: £100-£350
- 38cxi Repair: £100-£350
- Betacom4 Repair: £120-250
- Compact Repair: £120-250
- Easicom3 Combi Repair: £150-250
- Easicom3 System Repair: £300-500
- Energy Repair: £120-250
- Energy Regular Repair: £100-200
- Energy System Repair: £150-300
- Energy7 Combi Repair: £120-250
- Energy7 Regular Repair: £150-300
- Energy7 System Repair: £120-250
- Essential Repair: £120-250
- Flexicom 24c / 28c Repair: £150-250
- MicraCom Repair: £150-300
- Sustain 12s Repair: £80-£350
- Ultimate 3 25R Repair: £100-200
- Ultimate3 Combi Repair: £120-250
- Ultimate3 System Repair: £150-300
Source
Glow-worm F.70 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