Glow Worm 38cxi boiler, losing pressure when heating off.

[SteveBarum]

Heating on timer and when off pressure indicator has started to read 0.6 bar and red warning light flashes. When pressure is re-set to 1.0 bar heating can be switched on and it will remain on until timer switches off. Pressure indicator then falls to 0.6 bar again and red warning light flashes and cycle starts again where heating will not switch on.

 

[kevplumb]

check the pressure with the boiler running

check the auto air vent

check the prv pipe outside

check condense pipe with boiler off

 

[SteveBarum]

check the pressure with the boiler running Could only read temp on dial when runnuning. So adjusted pressure to 1.3 bar and switched on around 9.00am left running and working ok until I switched off at 19.00 hrs. pressure read 1.7 bar.waited 2 hours with heating off and pressure dropped to 1.0 bar. Turned temp down to 40 deg anmd left on overnight from 21.00 hrs. Just switched off again at 10.30 hrs and pressure reading 1.3 bar.

check the auto air vent Seems ok.

check the prv pipe outside Seems ok

check condense pipe with boiler off seems ok :

 

[snoozy]

Hi, just googled for problem help which sounds very similar. Pressure keeps dropping off, have to turn 'blue' knob to increase pressure. Once reached certain level green light illuminates and you hear system kick into life again. The close off same valve by turning 'blue' knob other way. Its a bit random when this happens. Glow worm engineer suggested it was due to leak or expansion vessel? no sign of leaks so wondering if problem with expansion vessel???

 

[chesterscla]

check the pressure switch i just had the same problem .!!!!

Hi, just googled for problem help which sounds very similar. Pressure keeps dropping off, have to turn 'blue' knob to increase pressure. Once reached certain level green light illuminates and you hear system kick into life again. The close off same valve by turning 'blue' knob other way. Its a bit random when this happens. Glow worm engineer suggested it was due to leak or expansion vessel? no sign of leaks so wondering if problem with expansion vessel???