Water not hot after changing Room Thermostat

[Rincewindwiz]

HI All
My room thermostat (Digistat 1) gave up the ghost in the summer so I replaced it with a Digistat+3 (same backplate)
It was fine until recently (it had got colder!) when I noticed that the radiators were not as hot as they used to be and the hot water was not as hot
For example: I can shower using just hot water (no cold required)
The heating is now on , the controller is showing a flame (and has been for ages) but the radiators are only luke warm.
So I am confused as I did not think the room thermostat affected the water temperature!!
But there is a small grey box in the side of the HW tank with wires coming out of it which go into the same collection of wires as the pump wires. So I guess this might be a temperature sensor.
But I cant see anywhere on the digistat3+ to set water temperature nor anywhere on the hot water tank

Any suggestions as to how I get hotter water?

 

[ShaunCorbs]

You should have a timer somewhere as the stat is just for the heating to the rads

 

[Knappers]

Not seen a setup quite like that before

 

[ShaunCorbs]

Thermal store

 

[Rincewindwiz]

The only other timer is on the boiler and that turns on and off when it supposed to. But I dont think the issue is not turning the heat on rather that the water is not hot enough. Must presumably be a temperature control somewhere to stop the water from boiling?
I'll try the boiler 'boost' button (turns it on regardless of the timer) tomorrow and see if that makes a difference.

 

[ShaunCorbs]

It works in reverse to a stnd hot water cylinder so at a guess the right red pump should be on when the store needs heating (should be an arrow point up on the body of the pump)

 

[Rincewindwiz]

Situation much better this morning.
Pipes same temp above and below both pumps (both throbbing nicely)
Red has arrow but it points down?! - IIRC I replaced this pump a few years ago. Did I screw up? It seems to work OK
Hot water back at normal temp
Will check (Again) stat timing and see how things progress thru the day.
Thanks to all who have responded

 

[Basher]

Trusting that the flex hanging from the choc. block on the left of the photo is a temporary arrangement while you investigate! It needs making safe by an enclosure incorporating cable strain relief, and no visible single insulation. But you know all that!

 

[Rincewindwiz]

Trusting that the flex hanging from the choc. block on the left of the photo is a temporary arrangement while you investigate!

Indeed so

 

[ShaunCorbs]

Situation much better this morning.
Pipes same temp above and below both pumps (both throbbing nicely)
Red has arrow but it points down?! - IIRC I replaced this pump a few years ago. Did I screw up? It seems to work OK
Hot water back at normal temp
Will check (Again) stat timing and see how things progress thru the day.
Thanks to all who have responded

That’s the one to the rads ok the green one is from the boiler so when boosting / turning on this one should run