my modena 80e needs toppin up as loosin pressure from wall exsternal pipe runs fine wen topped up but if you dont use it will slowly empty any advice

countoff, October 2010

thanks for advice got ferroli in changed exspansion valve working like a good en not exspensive either can give number if needed thanx

kelty, November 2010

Addition to answer given, yes it could be over expansion if no air in expansion vessel, also could be dirt in PRV or spring is week

RAWPLUMB, November 2010

check the pressure in the expantion vessel
if water come out of the valve it will need replacing
the presure on the system gauge has to be zero
the pressure in the expantion vessel should be about 1 bar with the pressure in the system at zero
once you have done that represurize system to 1 bar

b, October 2010