Hi all, girlfriend has had a shower fitted recently, the mixing bar type, the cold water supply to the shower has been plumbed into the mains cold water feed. The plumber fitted a single pump to the hot water supply because the cold water pressure was too great to allow the hot water into the mixing bar of the shower. But because the pressure of the cold water was so high, it wouldnt allow the flow switch in the shower to operate. The plumber solved this by putting a water pressure reduction valve onto the cold water feed, which has worked and the pump now operates. The problem which has occurred since then, is that when the pump is not operating the cold water is entering the mixing bar and is forcing its way through the pump and is backfilling the cold water tank in the loft, and therefore is overflowing constantly. I suggested that putting a check valve/one way flow control valve onto the hot water line to stop the cold water forcing its way through, i think this would be an easy solution. But my partner has spoken to a reputable plumber and he says this is just a short term fix and he wont do it. Can anybody tell me if this check valve would fix the problem, and if this is the case, why is the other plumber suggested this is only a short term fix.
thanks Neil