BoilerFaultCodesWhat the manual says
Manufacturer manualWater Pressure Switch Not Operated (Primary water pressure is less than 0.5 bar)
What causes this fault?
This fault occurs when the internal sensor detects that there is not enough water inside the central heating system to operate safely. The most common reason is a gradual loss of pressure through a small leak on a radiator valve or because the system was recently bled without being topped up.
This fault is more frequent in autumn when homeowners turn their heating back on for the first time, as the change in temperature and manual bleeding of radiators often causes the pressure to drop.
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 E119: no call-out fees, no surprise bills.
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Related fault codes
All 11 fault codes on the Promax System HE Plus
Seeing a different code? Every code this model can display, in one place.