Combi boiler system,one radiator only heats up at the bottom

[Jemma]

Hi,

I have a combi boiler system, one of the radiators only heats up at the bottom.
I have tried bleeding it, but not sure if I should be doing this cause it is a combi set up, refilled the boiler after, this did not help.
I have a worcester boiler.
Any ideas?

 

[Bahco]

Keep bleeding it until water escapes and refill pressure. If no joy, balance your system

 

[PEDANTICVINDICTIVEMAN]

System empty.