Issue with new rad staying cool at the bottom

[Dougie212]

I've just fitted a new radiator with Drayton TRV and lockshield. I understand that the valves are bi flow and so for ease of access the TRV is on the right of the radiator. The radiator is heating up but is staying cool at the bottom and I have lifted the floorboard at the trv end and that is also cool too. I have isolated that radiator and it does eventually warm through but doesn't heat up as normal, the bottom and right hand corner almost just conducts the heat rather than gets hot if that's makes sense. I've tested the pin in the trv and it will push down a little and springs back up. I was going to try and put some central heating cleaner through and see if that helped, and either move the sludge or release a possible airlock but I'm a bit baffled. Would the easiest thing be to take the rad off and make sure the trv is opening? I'm stumped... thanks in advance.

 

[Dougie212]

In addition my boiler is a combi boiler and all the other rads are working perfectly.

 

[slippyr4]

Did it get nice and hot before you changed the valves?

 

[Dougie212]

It's a complete new, larger rad so I have extended the pipework but only to fit the new width, but yes the old radiator did get hot.

 

[slippyr4]

Is the lockshield valve open?

 

[Dougie212]

It is yep. I did fall foul to that when I fitted it. That's fully open. I've not used a trv before, have since fitted another and it's fine. Just seems weird that nothing seems to be getting through it...

 

[gigz]

Probably needs balancing. See FAQ section.

 

[Dougie212]

I thought thought that balancing controlled the heat of the radiators so as it was even over all the radiators. I don't think anything is flowing out through the trv side of my new radiator. Would that still be solved with balancing?