rad cold

[ukbill]

hi all my rads are ok they all have termo valves and anti tamper valves on the return which need a star key to adjust
but 1 rad wont get hot it was ok then just went off i have checked the valves all seem ok on the flow pipe there is a drain valve i put a hose on this and drained water then the water started to get hot and flowed through the rad but in reverse flow so it was returnin through the thermo
i let it run for a while then stopped it but within around 2 hrs it wen cold
the flow and return pipes are also cold as if not hot water is in them pipes any help plz

 

[Biguns]

Have you tried turning all other rads off and see if this one warms up

 

[tincup]

Take the top of the TRV off. Does it get hot?

 

[ukbill]

no i havent tried to turn the other rads off
do u mean at the lockshield end,because these need a star key
they are preset tamper proof
i have tried the trv and its is working ok

 

[Biguns]

Just turn off all rads (except the problem one) at the TRV and see if the prob. one gets hot