The BG Engineer turned up with the heat exchanger and changed it. That didn't solve the problem. So, he spent another 2-3 hrs changing the valve that seperates the heating from the hot water 9which was changed last year), but the problem was still not solved.
Infact the problem got a bit more extream. i.e. When the water was hot, it was hoter than before, and when it cooled down, it was cooler than before. That is probably because there was no dirt in those new parts.
Eventually when he reduced the flow of the water into the combi boiler, the water remained hot. It was ok for the kitchen and the bathroom sink, but the pressure wasn't enough for the shower.
So, situation is slightky better, but the shower remains a problem.
Infact the problem got a bit more extream. i.e. When the water was hot, it was hoter than before, and when it cooled down, it was cooler than before. That is probably because there was no dirt in those new parts.
Eventually when he reduced the flow of the water into the combi boiler, the water remained hot. It was ok for the kitchen and the bathroom sink, but the pressure wasn't enough for the shower.
So, situation is slightky better, but the shower remains a problem.