Hot water keeps running through radiators - even when off! (PICS inside)

[New2DIYing]

Hi guys

So my upstairs radiators always get warm/hot even when the central heating is turned off.

We called a plumber in the summer who turned the upstairs radiators off at the valves... However this resulted in the downstairs radiators getting hot instead! Something that never used to happen before.

Given its winter all the valves are currently open (which means the upstairs radiators are always warm - they get much hotter when the central heating is actually turned on).

Is there a way to stop my hot water constantly running through the radiators? I have included some pics below to show the tank system we have in the loft:

Thanks!

 

[picasso]

Got a three port valve or two x two port valves ? (should look something like this)

 

[AGAS]

instead of your plumber turning your rad valves off why didn't he look at your diverter valve ?