BoilerFaultCodesWhat the manual says
Manufacturer manualLack of water fault (<0.5b)
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe operating level, causing the boiler to shut down to protect the internal components. The most common reasons are a small leak somewhere in your pipework or radiators, or the pressure being manually drained during recent maintenance without being refilled.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time, as the change in temperature can highlight small leaks or air pockets that developed over the summer.
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 0.5bar: no call-out fees, no surprise bills.
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