BoilerFaultCodesGlow-worm d.17 Fault Code
Also written as D17 — same fault.
The Glow-worm d.17 fault code means: your boiler has detected that the water inside the system is not circulating or heating correctly, which usually suggests a problem with the way it senses the temperature or moves water around.. It appears on 6 Glow-worm models in our database.
Technical description: Flow or Return temperature control
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like d.17: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Glow-worm models that show the d.17 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm d.17 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 Easicom 24 manual (PDF)
- Glow-worm Energy7 Combi manual (PDF)
- Glow-worm Flexicom 24c / 28c manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026