Boiler Over Pressure

The pressure guage on our boiler (a worcester 28i combi), was found to be reading at 2bar, the other day, when there was no heating on. We dropped the pressure back down to 1 bar via the relief valve yet within a day the pressure had increased back up to 2 again.

At this point I thought it was the quick fill line, however we disconnected this completely, so its not this.

The expansion vessel was measured at one bar. So I do not think it is a fualt here.

The only thing that stops the pressure rising is by isolating the inlet on the domestic hot water.

Therefore I think there is a leak between the heating and domestic pipes on the heat exchanger perhaps in the pipe walls or at the inliet/outlet. A plumber has since suggested this is impossible, but I think he may be avoiding the inevitable work!!!

Has anyone come across this before or do people have any other suggestions.

cheers

dchaney, welcome to the forum

I'm sorry (well actually not ) I've never come across this problem. Why don't you ask for a second opinion by letting another plumber look at it?

Just to let you know, I replaced the HX myself because I could not find a plumber to do it and the problem has been solved. I'm very suprised not to hear of this problem before!!!

Dave

Wow! That's great, dchaney {Feel-good-000200BB}
Care to explain the method you followed replacing it?