D.18 Low
Your boiler is currently set to run the pump continuously, which is usually a temporary setting used during maintenance or to prevent freezing.
Technical description: Pump mode return
Typical repair cost: £0-120 (including labour)
DIY fix possible
Check if the 'Comfort' or 'Antifreeze' modes are active in your settingsTurn the boiler off and back on at the fused spur switch to reset the electronicsCheck if your external room thermostat is calling for heat continuously
Protect yourself from future repair bills
A boiler cover plan would cover faults like D.18 — no call-out fees, no surprises.
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Parts commonly replaced
- External thermostat
- PCB (Main Control Board)
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