glowworm express 100 boiler - low ch water pressure flashing

[tomgreen78]

everything about the boiler is working fine now had problem losing water from prv but seems ok now, its just the light flashing for low central heating water pressure when the boiler is just in standby (no ct) and flashing when ct is on any help cheers.
could the sensor be at fault coming off prv?

boiler is glowworm express 100
pressure is staying at 1.4 bar

 

[HarrogateGas]

Try turning the main power switch off and back on (at the fused spur)

 

[tomgreen78]

simple things are always the best . thanks for that much appreciated