Thanks very much for this excellent forum.
In my bathroom upstairs I have a basin with cold and hot taps connected to a mixer. It has been working fine until a few days ago when the water from the hot water tap got very weak but it is hot. The cold water tap is fine.
I thought the problem was with the hot water handle so I swapped it with the cold one but the problem is still there.
The upstairs shower is working fine.
The other taps in the another upstairs basin were OK.
I have a conventional Hot Water System with the boiler in the kitchen and a storage cylinder upstairs.
Any help is appreciated.