Not very long ago my pipes started making a horrible howling noise from the hot water supply whilst running a bath, now the hot water tap only runs for about 2 minutes and then trickles and stops and has also moved to the sink and kitchen. Our cold water remains fine. Our heating system is a emmersion tank in my sons room upstairs, it only serves for hot water as we have a hot air system for our heating, so no radiators.
Any pipes that go up from the emmrsion heater go into the roof but then straight back down I believe into the electric shower in the bathroom.

Has anyone got a fix it for this situation? I would be eternaly greatfull.

Good morning,
When was the last time the hot water system was flushed and cleaned out?
It sure sounds like you have mineral buildup and some of that buildup broke off and is now clogging up your hot water pipes.
The "howling sound" you heard was pieces of the clog vibrating against a seat as the water rushed past it.
The answer to your problem is to first flush out the heater and then open up the valves, one by one, and flush the hot water branch and supply lines leading to each faucet. By electric shower are you referring to a preheating element or a pressure assist system? More questions? I'm as close as a click. Good luck. Tom