BoilerFaultCodesGlow-worm F.13 Fault Code
Also written as F13 — same fault.
The Glow-worm F.13 fault code means: your boiler is struggling to accurately measure the temperature of the water stored in your hot water cylinder because there is an electrical fault with the sensor cable.. It appears on 22 Glow-worm models in our database.
Technical description: Cylinder temperature sensor short circuit
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A cover plan would handle faults like F.13: no call-out fees, no surprise bills.
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Glow-worm models that show the F.13 fault code
Click a model for the full fault code list and model-specific repair notes.
- 30cxi Repair: £90-160
- 38cxi Repair: £90-160
- Betacom4 Repair: £120-200
- Compact Repair: £120-200
- Easicom3 Combi Repair: £120-220
- Easicom3 System Repair: £120-220
- Energy Repair: £120-220
- Energy Regular Repair: £120-200
- Energy System Repair: £120-180
- Energy7 Combi Repair: £120-220
- Energy7 Regular Repair: £120-220
- Energy7 System Repair: £120-200
- Essential Repair: £120-220
- Flexicom 24c / 28c Repair: £120-200
- Flexicom CXi Repair: £150-250
- MicraCom Repair: £120-220
- Sustain 12s Repair: £90-160
- Ultimate 3 25R Repair: £120-220
- Ultimate3 Combi Repair: £120-220
- Ultimate3 System Repair: £120-200
- Ultracom 2 SXI Repair: £250-450
- Ultracom hxi Repair: £90-160
Source
Glow-worm F.13 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