I had the Central Heating boiler installed about 4.5 years ago, by British Gas. They powerflushed the system at that time, and replaced the boiler and hot water tank, pump and controller.
This week a radiator in the bathroom (which is a bit newer as we had the bathroom redone) went cold towards the top, so I bled it and it warmed again. However, the next morning all the radiators were cold, and the hot water was lukewarm. Bleeding the bathroom radiator again led to lots of gurgling and things warming up again. I've had a British Gas engineer out (on the service contract) and he said that the pump was on too high a setting (don't think I've changed it since it was instaleld), he turned it down and said if I kept bleeding the radiator it'll be ok in a few days. He then said that it needed a powerflush, as there was lots of metal(?) collecting near the pump (in a sort of squarish copper box at a junction).
I do live in a very hard water area, but should it really need powerflushing allready? They said it would be =A3400, would I get it cheaper elsewhere? From what I've read of diy solutions I don't think I'd like to try that as I'm quite cack handed and don't really want to screw it up more.
Ta
John