Cold radiator

[peter x]

Ok guys solve this one I have a radiator in my my loft conversion bedroom was done in 2004 so 20 years of frustration it was changed for a bigger radiator as the original was so hit and miss ,it would get some heat in it nut pretty rubbish..I have drained the system numerous times used cleaner and inhibitor the ensuite towel rail only 3 to 4 feet away gets very hot but does loose heat in afew bars at the top after a while and bleed it and it's fine no issues with the boiled loosing pressure either .But the loft bedroom radiator is stone cold now and has been for years tried balancing the system turning down the valves on the downstairs radiators and first floor etc ...in years gone by the loft radiator would get 3 quarters hot but their was no air in it only water comes out the bleed valve so now just use a plug in oil heater now and again .

 

[Wayners]

Turn off all the rads except the problem one. What happens?

 

[Johntheo5]

Ok guys solve this one I have a radiator in my my loft conversion bedroom was done in 2004 so 20 years of frustration it was changed for a bigger radiator as the original was so hit and miss ,it would get some heat in it nut pretty rubbish..I have drained the system numerous times used cleaner and inhibitor the ensuite towel rail only 3 to 4 feet away gets very hot but does loose heat in afew bars at the top after a while and bleed it and it's fine no issues with the boiled loosing pressure either .But the loft bedroom radiator is stone cold now and has been for years tried balancing the system turning down the valves on the downstairs radiators and first floor etc ...in years gone by the loft radiator would get 3 quarters hot but their was no air in it only water comes out the bleed valve so now just use a plug in oil heater now and again .

Is it a sealed or open vented system.?
Is it a gas or oil fired boiler?
Where is the boiler located?
If oil fired where is the circ pump located.?
What make/model/mode/setting is the pump.?

I hava a oil fired boiler on the ground floor with a 6M circ pump adjacent to it, pumping into the boiler and servicing 10 rads at a head of 3/3.5M, one rad is in the attic converted bedroom, the system is open vented with the feed&expansion cistern mounted ~ 1.5M above the rad, no problems with circulating this rad even though it does run with a very slight negative pressure because if the air vent is opened with the system on then no water comes out the vent but will as soon as you stop the system.
So yours, IMO should be able to do likewise, will have a better idea of it if you reply to the above questions.