hot upstairs cold downstairs

[AnonymousImport]

hi, radiators and especially the hot water tank are hot upstairs while the rads. downstairs are only luke warm.I've bled all the rads. and on change. Its a closed system with the flow pipe going upstairs firstly and then back down for the downstairs rads. Is this the way its meant to work ? There is one pump beside the boiler and an electric valve on the flow pipe going upstairs.
thanks for any help.

 

[AnonymousImport]

have you checked the pump

 

[AnonymousImport]

yes i've checked the pump. ok. There is hot water in the expansion tank in the attic and condenstion on the floor. Any suggestions , please.

 

[breezer]

I am not a heating engineer but does the valve not control the flow to downstairs? does it have a manual over ride? if so what happens if you over ride it?

 

[AnonymousImport]

Yes , well done . The manual setting works and the radiators are now hot downstairs.
Only problem is the hot water still going up into the expansion tank.
Can a valve be fitted to turn off the flow when it reaches a certain temperature going to the hot water tank ?
I Appreciate your help sofar. Thanks.