Water is from mains. It is only in bathroom. The rest of the house is ok.
Yes we have hot water
The tap is a modern lift and move to L for hot and R for cold water. To L hot water comes out. To R no water comes out of tap.
Into the modern toilet system there is a drip of water which seems to be unregulated.
Bath tap works ok so it would appear to be something that has only to do with the basin tap and the toilet flush system. Both of which are in the same box. Let me know 8if you want a photo.
Nothing has been switched off. It has just happened that the water is not running and there is no flush on the loo.