from a cold start my worcester boiler pressure is 1 bar, but when i switch the central heating on and it warms up the pressure rockets upto 4 bar and water trickles out of the overflow pipe. I have tried draining the system and refilling but i still have the problem. Help!!!!
Any advice please.

Rachel, May 2008

Before you start paying silly money for call outs, check if you have left the "loop" attached, disconnect it from the supply end to check the valve is leaking. Mine was. £3 fix for a new valve.

Luccarlo, April 2014

Have exactly the same problem. Changed the pressure vessel but that didnt solve the problem.
Worcester technical advice seemed to think there maybe a cross leak on the heat exchanger and have quoted £285 for the repair including 12 months cover, not bad me thinks...

grant2491, January 2011

i got ch working but no hot water

aziz, December 2010

Firstly,put tyre pressure gauge on the expansion vessel should be .5bar If it is not, does water come out, if it does pressure vessel propably faulty, but its far more likely to be heat exchanger had problems when the boilers have been fitted without limescale filters.To proove it turn off water supply to boiler, reset boiler pressure to 1.5bar (cold).Turn on heating if its leetching through to the heat exchanger the pressure should not rise to the same extent,it will of course rise since your heating water but not to same pressure. Replace heat exchanger

P Creed Plumbing & Heating, December 2009

I had the same problem with mine.
Turned out to be the heat exchanger leaking between ch and dhw.
About £240 for exchanger plus fitting. ouch!
I fitted mine myself last christmas eve.

Steve, May 2008

its the expansion vessel at fault if it only happens when heating put on

iain, May 2008

if your filling loop is still connected try disconnecting it as it may be passing through the loop, if not it sounds like the expansion vessel at the back of the boiler its usually a large red drum at the back of the boiler, im not sure if the filling loop is an integral loop on your boiler

paul, May 2008