my mate just bought a house with a junior 28 combi, it had been standing for a while as the previous owner was in a home, the boiler is only 4 yrs old and is a really bad install , heating water is totally black , around the flue not sealed ect ect , I opened it up as he told me it would not come on, pressure was on 0 . topped it up , and fired it, the fan shorted and did a loud bang, and the pump had burnt out, replaced both and stuck an analyser on it, everything was ok , I told him id service it in a week when I had more time and clean the system out ect , plus he had some other bits to do . three days later he calls me , pressure gone down again ( I suspect this to be a leak under the floor as the pipes and rads look really old and unprotected) told me there was a few drips of water coming out from around the pressure gauage. took the cover off and there had been about 20mm of water standing in the bottom of the boiler. the stain marks seem to be running down from the grey plastic flue joint inside , I thought maybe it could be a blocked condenstate trap , so I cleaned it all out and brushed inside of the burner out and poured water down to clean if you know what I mean. is there anything else it could be? thanks.