118 High
Your boiler has lost water pressure, which means there isn't enough water in the system to keep it running safely.
Technical description: All Boilers
Typical repair cost: £0-120 (including labour)
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the one or two taps/valves on the loop until you hear water flowing.Watch the pressure gauge and close the valves once the needle reaches between 1 and 1.5 bar.
Protect yourself from future repair bills
A boiler cover plan would cover faults like 118 — no call-out fees, no surprises.
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Parts commonly replaced
- Filling loop
- Expansion vessel
- Pressure sensor
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