New Rad. Lock Shield pipe cold TRV Hot

steve1500

So fitted new Rad in Summer ( done plenty around the house)

As it says TRV pipe nice and hot, but lock shield pipe cold. Turned wide open but still nothing. so a Rad that is only partially warm

Doesn't need bleeding and done balancing. All others rads fine

Any suggestions

TIA

jonnydeppiwish!

Does the lock shield actually open and close? Close both, then disconnect the lock shield from the radiator. Let the radiator drain, then slowly open the lock shield. 

subjecttocontract

Close down all the other radiators and see if it gets hot.

steve1500

Thanks - was my thought about the lockshield - is it working. But will try closing all the other Rads off first

Vitor

Double-check the lockshield valve, the spindle can sometimes shear or not actually open even though it turns.

Try cracking the union on the lockshield side slightly (with a towel ready) to see if water comes through; if not, there’s a blockage or no flow from the return pipe.

steve1500

My gut says faulty lockshield. Thanks

OliverLacon

It could be an air lock in the pipework. Try turn off all the other radiators an domestic hot water. On the radiator that does not work - open the lock shield fully and also the TRV. The full force of the pump pressure will be applied to the pipework and radiator. If there is an airlock it should be forced out.

jefaz07

Try and take and the head off the TRV. When they fail, the fail closed.