Hello I hope someone can help.
My CH combi boiler seems to lose pressure when the boiler is running. It is
set at 1 bar cold but when it is running (burner on pump running) this falls
to about 1/2 bar. If you then turn this off to fill using the fill loop the
pressure gauge immediately goes back to close to the 1 bar.
Should I set the pressure with the boiler running? or is it OK
Any help appreciated.