Could be airlocked, if you have a mixer tap - place you thumb over the end and open the hot and cold tap - the cold water will backfill the hot water pipes.
If you don't have a mixer - use a short cutting of hose to connect the two taps.
apparently their is also no cold water, nor is the toilet cistern filling..all this is in the bathroom, i assume all are fed from same supply and had hoped to find somewhere in supply shut-off valve or at least a compression joint i could have loosened, but without luck...is their anyother way to force air out ?....
unfortunately it is also the cold water..all this in the bathroom..hoped to find a stop-cock or compression fitment to release any air but no luck..is their any other way to clean the airlock
Check the ball valve in the tank - it can't be full, it's very unlikely to have an airlock in the hot water pipework and the cold water pipework - if no valves have been tuned off - the cold water taps in the bathroom and the cylinder must be fed from the same cold water tank in the loft.