1st floor rads not working

[Od]

Hi All

I have 35 rads over 5 floors on a f & e system and the 13 rads on the 1st floor are not getting hot during normal operation. there are two drain valves on the toilet rad on the 1st floor, one either side.
now if i open the drain valve on the left 9 of the rads will heat up and if i open the drain valve on the right the other 4 rads heat up but the first 9 go cold.
Can anyone shred some light on this?

many thanks
OD

 

[past3bar]

Do you have separate controllers on each floor i.e. roomstats?
Do you have water in the F&E tank?
Have you tried shutting all other rads down on other floors to see if the heated water pushes through?

 

[Od]

All the rads work from 1 control, yes here's water in the f & e tank, I've shut all the other rad down but it had no effect, i've drain the entire system, refilled and bleed every rad, i've set the pump to the high speed (for about 45mins) to no effect, and none of the rads are blocked.

thanks
Od

 

[past3bar]

If you have a cylinder to heat hot water is the system controlled by a 2 or 3 port valve and did you make sure this was manually open before and during filling?
Make doubly sure the radiator valves are open at both ends of each rad.
It sounds like you may have got air or dirt trapped in the system.
If you have a drain on the bottom of the system you could try attaching a hose to the mains, making sure you employ a suitable backflow prevention device, and fill the system from the bottom. Take care to make sure the F&E tank overflow is up to scratch.