BoilerFaultCodesWhat the manual says
Manufacturer manualInsufficient water pressure in the heating system
What causes this fault?
This fault occurs when the boiler's internal sensors detect a lack of water, meaning there isn't enough pressure to safely transfer heat away from the burner. The most common reason is a slow leak somewhere in your radiator system or a component inside the boiler, such as the air vent, letting water escape over time.
This issue often surfaces in autumn when the heating is turned back on after summer, as the change in temperature can cause weakened seals to leak or air pockets to move through the pipes.
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.
Avoid the next call-out bill
A cover plan would handle faults like F.22: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.