How can I get the pressure back in my hot tap?

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