BoilerFaultCodesWhat the manual says
Manufacturer manualFill central heating system, pressure 0.7bar min.
What causes this fault?
This fault occurs when there isn't enough water circulating in your central heating system to operate safely. The most common reasons are a slow leak from a radiator valve or pipework, or simply that the system needs topping up after you have bled air from your radiators.
This issue is frequently seen in autumn when homeowners turn their heating back on for the first time after summer, revealing pressure drops that occurred while the system was idle.
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 RED NEON: no call-out fees, no surprise bills.
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All 7 fault codes on the Fuelsaver Complheat 40 55
Seeing a different code? Every code this model can display, in one place.
Related guides you might find useful
Boiler keeps losing pressure
Six most common causes of dropping pressure.
Read →What pressure should my boiler be?
1 to 1.5 bar when cold on most UK boilers, from the manuals.
Read →Hot water works but heating does not
On a combi it is usually the diverter valve. On a system boiler, the motorised valve.
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