Swapped radiator now cold?

[Blueflame94]

Good evening,

Pretty new to this plumbing game.
The other day I changed a radiator one for one swap, had to resolder a bit of pipe work either side but that’s it.

It’s ran on 10mm copper tails flow/return. Once system was filled back up every other rad got hot apart from the new one. Both flow/return pipes were stone cold. Lockshield and trv both open.

Now when I changed the rad I drained it from one of the valves on that radiator. My only guess is draining it down from there has pushed sludge from rest of the system into that pipe work blocking the flow.

I ran out of time but my plan was to take rad off of the wall and open each side individually through drain down hose to check both sides had flow?

There is no air left in any rads. If it was the trv/lockshield the flow pipe would be hot up to the valve. Does this leave the only option being a blockage from draining the system? Going to go back next week, close all other rads up and force water through that radiator and see what happens.

Thanks

 

[terryplumb]

Turn off every working radiator by it's TRV. See if cold radiator now heats up.