Every time I turn the hot tap on

[fortwilliam]

Hi
Just registered to see if anyone can give me some advice before I call somebody in.

Every single time we turn the hot tap on whether it is in the kitchen or bathroom the tank fires up and it takes a wee while for the hot water to come through, the tank also doesn't seem to come on through the night and late afternoon anymore, Could it be something to do with the thermostat?

Confused

 

[Gary59]

If a 'Tank' was firing at me, I'd run, unless I had some heavy artillery of my own........