Heating won’t come on after draining system

[Jayjay99]

Hi, I drained the the central heating, to remove a radiator. After refilling it, the heating now won’t work.
It’s a combi .
I’m getting this symbol

 

[Jayjay99]

I’m now getting code F22
It’s a glow worm

 

[ShaunCorbs]

Air locked prob

Turn all but the closest rad off upstairs ideally then stick boiler on with just the one upstairs rad calling for heat