Cold central heating pipework

[Loubanez]

Plumbed some pipework in my kitchen for a new radiator last year, now the kitchen is completed it's time to fit the rad, although now i can't remember which pipe is the flow and which is the return, with the pipework hidden i thought I could solve this by turning the heat on and seeing which pipe heat up first, the problem is they both remain cold??? Any suggestions or does it even matter? Won't be any trv going on.
Thanks

 

[townfanjon]

Doesn’t matter either way

 

[Scott_D]

Why no Trv? Especially in a kitchen which gets pretty warm when cooking

 

[Loubanez]

Why no Trv? Especially in a kitchen which gets pretty warm when cooking[/QUOTE

If I fit a tvr will I have to locate which pipe is which?
How come they both remain cold?

 

[DXCross]

I doubt the pipework would get hot due to the lack of ‘flow’ fit a bi-flow trv as these can be plumbed on either flow or return

 

[Best]

If you must find out which is the flow pipe, just connect a piece of pipe between the 2 rad valves and open the valves when system cold. Then just see which valve heats first when boiler starts

 

[Jimmy18]

I would feel the pipe(s) which the new rad is teed into personally. The first one to heat up is the flow.
Although the pipework is hidden. You must of teed into somewhere unless buried.

 

[Mastermixlee]

Yep as said above won't heat up until flow passing through. So connect up either way round and fit a bi-directional TRV.

Only potential hiccup is if its a tall vertical style radiator as some of these have a plate inside the flow side (generally have stickers on rear of rad) that encourages even heatup. If these rads are put on with reversed flow then sometimes they suffer with uneven heat across the radiator.