My friend has a Baxi 105E combi I've just had a look at a fault on it and I just want to confirm my findings.
The problem is that first they said they we're loosing pressure but no leaks and the blowoff is dripping. When looked into it the blowoff seems fine the boiler is working as it should but the pressure seems to rise very quickly when it is on CH. When the a hot water tap is opened the pressure starts to increase after you close it drops a little but as it turns back to CH the pressure rises quickly again.
I'm thinking it is the heat exchange that is leaking. But I was wondering if any one else had any idea?