The pressure gauge keeps dropping rapidly to zero and the boiler turns itself off. I have topped up the pressure 3 times today but it keeps dropping. We have recently removed 3 radiators which have been capped and they are not letting by. There appear to be no water leaks so I am really stumped. Any ideas ?

Siobhan, May 2012

worcester greenstar 40cdi
GCN 41-311-72
megaflow [UNVENTED INDIRECT HOT WATER CYLINDER]
constant pressure loss
no visible signs of leaks
check pressure relief valve on side of megaflow
if PRV is constantly dripping chances are coil inside megaflow has punctured causing pressure loss

check out youtube
unvented hot water systems
plumber parts
for explanation of terms used here

manwithnoname, May 2012

Forgot to say. The boiler is a Worcester greenstar 40CDi conventional boiler.

Siobhan, May 2012