In my bathroom the basin hot tap runs fine whilst cold water comes out but as it heats up it slows down to a virtual stop. The bath tap is fine and so is the kitchen tap. The basin taps are single taps (not mixer)
We have recently had our heating flushed through as we had no heat in the rads upstairs. I have noticed that the last rad in the system now needs to be bleed often (you can hear air bubbling away) so we must have an air leak somewhere. Are these related?

Holly, February 2011

It sounds as though there may be an air lock on the domestic hot water. If the system is tank fed
(+ copper cylinder) and not a combi boiler, place the ends of a hose pipe on each basin tap, then opening the hot first then the cold, this should force air out of the hot pipe. Do this for ten to twenty seconds, turn off both taps, disconnect the hose pipe and after gurgling and sputtering, the hot should return to normal. If not the problem could be a boiler problem.
Sorry about the rad, could be the system is settling down after draining, you could try turning the pump down a notch and see if that works. But keep bleeding it and balance your system using the valves for best performance.

best policy, February 2011