HOW CAN I STOP OVER PRESSURE?

I have exactly the same problem with my excell. I have read every thread on all of these mend it sites, I have stripped my boiler down and checked/replaced all relivent parts but this problem has beat me. No boiler engineer I've had out has fixed it in the 5 years I've been at my house. What was the problem and if you fixed it what was the solution???????? I've come to the conclusion that the boiler is back filling off the central heating system. I don't know if this is correct or a mythical conclusion I've created BUT I need or would like an answer PLEASE! Also can I turn the burner heat up so the water gets hotter in winter. It's a nightmare. I have to run my hot water tap very low to get hot water through it. Obviously ground water temp is alot lower in winter than in summer. Any suggestions please experts. Thanks Allan (a beaten man).

Allan Warnock
December 2008

The domestic hot water heat exchanger must have a leak between the central heating and DHW sides.
You need another one of these:
http://cgi.ebay.co.uk/vokera-maxin-eclispe-heat-exchanger_W0QQitemZ270262259593QQcmdZViewItem?hash=item270262259593&_trkparms=72%3A12%7C39%3A1%7C66%3A2%7C65%3A12&_trksid=p3286.c0.m14.l1318
(not sure if this is correct for the excell- check BEFORE you buy).

c
August 2008