BoilerFaultCodesWhat the manual says
Manufacturer manualSystem pressure dropped below 0.5 bar. The boiler will not light and it will be necessary to top up the pressure.
What causes this fault?
This fault occurs when the water pressure inside your heating system drops below a safe working level, causing the boiler to shut down to prevent damage. The most common reasons for this are a leak somewhere in your radiators or pipework, or a failure of the internal expansion vessel which helps manage pressure changes.
This issue often appears when you turn your heating back on for the first time in autumn, as the system cools and contracts during the summer months.
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 P 0.4: no call-out fees, no surprise bills.
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