TRV valve installation - which side of radiator?

FlaatusGoat

What side of my radiator do I put these one, any obvious give aways? The pipe run and connection is the same on both side?

CliveOfIndia

Assuming they're bi-directional valves, which most are these days, then it doesn't really matter.  Conventional practice is to install them on the flow side - if you install a non-bi-directional valve on the return side then it can make a vibrating sound.  So for the sake of simplicity, stick to the flow side and then it doesn't matter which type of valve you have.

FlaatusGoat

CliveOfIndia said:

Assuming they're bi-directional valves, which most are these days, then it doesn't really matter.  Conventional practice is to install them on the flow side - if you install a non-bi-directional valve on the return side then it can make a vibrating sound.  So for the sake of simplicity, stick to the flow side and then it doesn't matter which type of valve you have.

Which is the flow side, left I presume? Thanks

FreeBear

The side that gets hot first as the CH system heats up will be the flow side.

Often, this is on the other side to the lockshield.

Lgas

FlaatusGoat said:

CliveOfIndia said:

Assuming they're bi-directional valves, which most are these days, then it doesn't really matter.  Conventional practice is to install them on the flow side - if you install a non-bi-directional valve on the return side then it can make a vibrating sound.  So for the sake of simplicity, stick to the flow side and then it doesn't matter which type of valve you have.

Which is the flow side, left I presume? Thanks

It entirely depends on how it was installed, could be either. The only way is to turn the heating on and feel which pipe gets hot first, and don't assume they're all the same.

ThisIsWeird

Make sure all the rads are actually on, then run your CH for just 2 or 3 minutes, then off again.
Go around them all with bits of paper and tape - 'flag' the warm(er) pipe tails, and that'll be the flows.
Since you seemingly have a choice, stick with convention and TRV the flows. Unless it is functionally better for it to be on the other end - ease of access, cosmetics, or to keep the TRV out of the sun or draughts. For any on the 'wrong' side, you could always leave a 'flow' label under their lockshield caps.

rob7475

It really makes no difference any more. The vast majority of TRV's are bi-directional these days.