BoilerFaultCodesGlow-worm F.73 Fault Code
Also written as F73 — same fault.
The Glow-worm F.73 fault code means: your boiler's internal water pressure sensor is failing to communicate, which means the system cannot accurately monitor its water levels and will stop working until resolved.. It appears on 15 Glow-worm models in our database.
Technical description: Fault: Water pressure sensor not connected or has short-circuited
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.73 fault code
Click a model for the full fault code list and model-specific repair notes.
- Betacom4 Repair: £120-£200
- Compact Repair: £150-250
- Easicom3 Combi Repair: £150-250
- Easicom3 System Repair: £150-250
- Energy Repair: £150-250
- Energy System Repair: £150-250
- Energy7 Combi Repair: £150-250
- Energy7 System Repair: £150-250
- Essential Repair: £150-250
- Flexicom 24c / 28c Repair: £150-250
- MicraCom Repair: £80-150
- Sustain 12s Repair: £140-220
- Ultimate 3 25R Repair: £150-250
- Ultimate3 Combi Repair: £150-250
- Ultimate3 System Repair: £150-250
Source
Glow-worm F.73 fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
- Glow-worm Betacom4 manual (PDF)
- Glow-worm Compact manual (PDF)
- Glow-worm Easicom3 Combi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026