My boiler is 14 years old. I had problems with the water heating in the shower, the engineer replaced the diverter valve (£160) in November but turned the central heating to a low setting (which I hadn't been aware of) consequently the radiators weren't fully heating. I had another engineer out yesterday who turned the central heating up but we now have the problem with water having to be turned down to a trickle to get warm water in the shower again. I really don't want the expense of a new boiler but is it worth having the heat plate replaced and about how much would it cost? Or any other advice would be welcome.