High
F22 on Glow-worm Ultimate 3 25s-A

Your boiler has automatically switched off because the water pressure inside the system has dropped too low.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

Fault F22 will be stored in the fault list when water pressure falls below 0.03 MPa (0.3 bar) and product switches off

From this model's manual
Verified against the Glow Worm/Glow Worm Ultimate3 System installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F23View →F24View →F75View →

All 39 fault codes on the Ultimate 3 25s-A

Seeing a different code? Every code this model can display, in one place.

F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.77F.78F.83F.84F.85F.86F.87F.88F.89F.97

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