How can I fix my mega flow HW/CH pressure problem?

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