2 rads cold

[mycek0]

Hi,
Got problem with 2 of 100 (big company) radiators. One is cold since I started work here, other one was fine, but I took the head off trv to check if it going to work on first one. Now both cold and I think I've tried everything.
When I was trying to get air out off it,it looked like there's no air at all and rad started to get warm a little bit, but quickly back to it coldnes.
Any ideas?
Thanks

 

[electronicsuk]

Air lock, poorly balanced?

 

[mycek0]

????????