no heat upstairs, combi

[Mcfly1]

Hi, we are struggling getting heat into out upstairs radiators, the system is pressurised and the downstairs ones all work fine. We turned the downstairs ones off and bled upstairs individually until hot water came through but as soon as downstairs are opened they take all the heat.

upstairs are piped with microbore (sigh)

any suggestions? thanks guys

 

[crashndie]

balanced the system out using the lock sheild valves go to the 1st rad closest to the boiler and shut the lsv ( lock shield valve) then open it half a turn then go to the 2nd rad shut it then open it 1/2 a turn and a bit an so on by shutting the valves down it will force the water to take a upstairs route hopefully. you may find the micro bore is starting to get blocked up

 

[jackpike]

it should'nt matter if its micro bore, as long as its piped up so each rad gets a flow and return, there may be a fundamental problem in the pipework, or maybe if manifolds have been used, they could be blocked with sludge,
its very strange to have the downstairs working ok, and upstairs not, its usually the opposite as heat rises, i think you may need to get a plumber in to investigate why this is,

 

[Razor900]

Was itconverted from an old gravity hot water system at some time?

Could possibly be a seized gravity check valve

 

[bengasman]

Has it ever worked 100%?