Cold Towel Radiator

[Centaur]

I have just replaced the radiator in my bathroom with a new towel radiator. Closed and emptied expansion tank, drained the system, fitted new lockdown valves and new radiator, bled the new radiator and all others on top floor, switched on boiler.
New radiator got hot, but system needed balancing.
At end of day lost all heat from new radiator and it has not got hot since.
Have bled all radiators with system off and on, still no luck. Last attempt, I had all radiators perfect and uniform temperature, except the new towel radiator (rad and supply pipes stone cold).
With the system off, water flows freely from the new radiator bleed valve with no air escaping or stutters.
Completely lost now - any advice on next steps please.

 

[Bahco]

Have you tried closing all rads except for problem one and then balancing.

 

[kaboom]

Doesn't quite fit in with you're explaination but- have you got a straight trv in there? Most straight ones are directional, ie flow must go with the arrow. If on back to front the water just won't go around. Can fox you if you have hot water in your system when you bleed and it goes into the rad. Seems ok but after that -goes cold and stays cold.

 

[thranjax]

Don't know what might be causing the problem you might like posting or asking the guys at http://www.warmup.me.uk who helped with my installation.

 

[softlad1971]

Thats a clever way of dropping in an advert....