108 High
Your boiler has lost water pressure and needs to be topped up to work properly.
Technical description: All Combi Boilers
Typical repair cost: £0-120 (including labour)
DIY fix possible
Locate the filling loop (usually two small taps or a blue lever) under the boiler.Slowly open the taps until you hear water flowing and watch the pressure gauge.Close both taps tightly once the needle reaches 1.5 bar.
Protect yourself from future repair bills
A boiler cover plan would cover faults like 108 — no call-out fees, no surprises.
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Parts commonly replaced
- Filling loop valve
- Expansion vessel
- Pressure sensor
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