F37 High
Your boiler has detected that the water pressure in the system is too low for it to operate safely.
Technical description: Error with system water pressure, possible pressure too low or water pressure switch is damaged
Typical repair cost: £100-220 (including labour)
DIY fix possible
Locate the filling loop (the flexible silver hose) underneath or near the boiler.Open the one or two taps on the filling loop slowly to let water into the system.Close the taps once the pressure gauge on the boiler reaches 1.5 bar.
Protect yourself from future repair bills
A boiler cover plan would cover faults like F37 — no call-out fees, no surprises.
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Parts commonly replaced
- Water pressure switch
- Expansion vessel recharge/replacement
- Filling loop valve
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