I'm only getting a very occasional flow of hot water for bathing & washing dishes from my gas central heating,approx once every month for about 2-3 hours only.When the water does eventually flow it flows fine like normal.
The radiators seem to be fine & I had the boiler serviced in January this year,it's a Glow Worm back boiler not a combi boiler.As usual the plumber didn't want to hang around to sort the hot water out for me then & he told me it's probably a faulty valve which I could probably sort myself.Is the valve he's on about the diverter valve?(thanks STEVELUP).If so,where can it be located,what does it look like & how can I tell whether it's faulty or not?
Any constructive ideas,comments,recommendations or links to related informative sites would be very welcomed.

p.s is RADON'S post below a reflection of his sarcastic personality?HAHA