Struggling to balance tall radiator

[markyyyyyy]

I’ve had a new boiler put in (ideal 24w max +) and replaced all my radiators (5 in total - 2 bed terraced house)

In my kitchen I have put in a 1800 x 600 double panel radiator

The only way I can get it hot all over is to turn off every other radiator and blast water through this one.

I balanced the system last night and all other radiators, the lock shields are between 1/4 and 1 full turn open, whereas the kitchen double panel one is fully open (4 full turns)

The pin on the TRV is moving up and down fine
The radiator has been installed the correct way up (as per stickers on radiator)

As I say the only way it can get hot all over is when the other radiators are closed… As soon as I start to open up the lock shields on the other radiators the temperature drops in the tall radiator

I have my water pressure set at 1 bar when cold. Do I need to increase his water pressure?

Should I turn off all TRV and lock shield on every rad apart from kitchen. Let heating run and blast it, and then turn the other rads on (TRV to max and lock shield 1/4 turn only?) while keeping TRV on kitchen on full?
Edit: there is no air in the system, all radiators have been bled fully
Thanks

 

[cross thread]

What size pipe did you run to the rad and how long?

 

[markyyyyyy]

Update:

I have opened all TRV valves and all lockshields to maximum and all radiators are boiling hot … so I’m just going to leave them as is

Maybe because it’s such a small house they all seem to heat up at the same speed

 

[markyyyyyy]

What size pipe did you run to the rad and how long?

15mm throughout the house