BoilerFaultCodesGlow-worm S.46 Fault Code
Also written as S46 — same fault.
The Glow-worm S.46 fault code means: your boiler has automatically activated its built-in winter protection mode because the internal temperature has dropped, and it is currently running at a low level to prevent the pipes from freezing.. It appears on 18 Glow-worm models in our database.
Technical description: Frost protection mode (Comfort): Minimum load
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 S.46 fault code
Click a model for the full fault code list and model-specific repair notes.
- Betacom4
- Compact Repair: £120-250
- Easicom3 Combi Repair: £100-250
- Easicom3 System
- Energy
- Energy Regular
- Energy System
- Energy2 30c
- Energy7 Combi
- Energy7 Regular
- Energy7 System
- Essential Repair: £120-250
- Flexicom 24c / 28c Repair: £120-250
- MicraCom Repair: £120-250
- Sustain 12s
- Ultimate 3 25R Repair: £120-250
- Ultimate3 Combi Repair: £120-250
- Ultimate3 System
Source
Glow-worm S.46 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 31 August 2026