radiator/heating problem

[kevfisher]

Was wondering if anyone could help....
Just fitted two new radiators down stairs on a sealed system and I decided that whilst the system was drained would fit TRVs to some of the other radiators.
The problem is the new radiators only seem to be getting warm at the top of the radiators and the "in" pipe is red hot and the "out" pipe is not even luke warm. All the other radiators are fine.
At first I thought I had maybe put the TRVs on the wrong side(not sure if this makes a difference) but this would surely stop the radiators from getting warm at all.
Any advice would be gratefully accepted
Thanks

 

[joe-90]

If the rads are quite old it may be that you have disturbed the sediment and it has all slumped to the bottom of the rads impeding the flow.


joe