central heating system (3 rads cold)

[dutchyids]

i have a split level flat, where the system is quite old but the boiler is fine.
3 rads in the down stairs living room are always cold. have carried out the following but still no good, any ideas ????
1/ power flushed system
2/ changed c/h pump
3/ repalced trvs
4/ replaced the 3 rads
5/ fitted magna clean
6/ tried to balance system

even shut down all rads in property but left just these 3 on, took a while but they got hot. when i turned the others back on they went cold again

 

[45yearsagasman]

Even after all your efforts you obviously still have a circulation problem.
Was it a pro powerflush and if not how did you do it?
Describe your system in more detail ie boiler,controls,fully pumped or not.

 

[joe-90]

What you have to remember is water is lazy. All it wants to do is take the easy route back to the boiler. If your downstairs rads are partially blocked with crud or the system isn't balanced it won't bother going down there.