tower radiator cold, but not balance?

[EdR]

I had a tower radiator put in last summer. Can't seem to get in contact with the plumber. It doesn't get properly hot.

I tried to fix by balancing the system. I am not a plumber. May not have got it right.

The gas central heating man came round today to service the boiler and I asked him what he recommended.

He suggested first that valves were wrong way round, then that we should turn up the heating.

Finally he said pipes either side were hot, and very bottom of the radiator is hot, but the top four and a bit feet of the radiator were cold. He said the water is not circulating through the radiator.

The system was thoroughly flushed in summer. The system does not need bleeding (it's sealed, and we checked).

He suggested flushing radiator through and testing to see whether water can circulate. He said there may be a blockage.

The radiator is at the end of the system.

Does his suggestion make sense? Is he right that the pipes on either side being hot means it's not a balancing issue?

When I open the bleeding valve water squirts out.

 

[EdR]

Forget it. I have just gone back to it, and its now boiling hot.

I wonder whether he found out what was wrong, corrected it, and couldnt bring himself to give me a fourth explanation.

Whatever. I'm warm.