HJ-09 High
Your boiler has detected that the water pressure is too low to operate safely, causing it to shut down temporarily.
Technical description: Low system pressure – increase the system pressure to 0.8 bar
Typical repair cost: £0-120 (including labour)
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the one or two taps/levers on the filling loop until you hear water moving.Watch the pressure gauge and close the taps firmly once the needle reaches 1.5 bar.
Protect yourself from future repair bills
A boiler cover plan would cover faults like HJ-09 — no call-out fees, no surprises.
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Parts commonly replaced
- Filling loop valve
- Pressure sensor
- Expansion vessel
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