Radiator TRVs and Bleed Valves

[Lew]

Hello all,

Firstly let me apologise, I'm sure my questions below have been asked time and time again.
*
I understand the old type TRVs (uni-directional) had to be installed on the flow side of the radiator only, however the newer TRVs (bi-directional) can be installed on either the flow or return side. With this in mind, should the bi-directional TRVs be installed the same way round on every radiator i.e. either all on the flow or all on the return? Am I correct to think that by installing some on the flow and some on the return that the system will not balance correctly?
*
Bleed valves, where should these be fitted? The same side as the a) incoming flow, b) diagonally opposite the incoming flow, c) it doesn't matter or d) something else?
*
I've been advised that it is good practice to hang radiators slightly off level to allow any air to move towards the bleed valve, this makes sense but is it correct?
*
Thanks in advance for your help and advice.

Sorry if text is large it won't change |
*
Regards,
*
Lewis

 

[pipefitter]

Hi..bi-directional valves can be fitted on either the flow or return & I wouldn't worry about putting them all on the same pipe ,i.e. all on the flow or all on the return ,they will work regardless of this.
We go into a lot of older properties and balance the systems and I'm sure the valves are not always on the same pipes.
And as for the Rads I would always hang them level ( or try too) you can get all of the air out if they are level.
& air vents also work on either side

 

[Mike Jackson]

I will always hang radiators level unless there is a windowsill etc. above them that makes them look wrong. In that case I will hang them parallel with the sill and make sure that the air vent is at the higher end.

 

[plumber0808]

It's best to still fit them on the flow if you can. If you fit a decent trv it will work fine on the return though. Buy a decent brand and not the cheapest they do as these can give you problems.
Radiator being level a must, can't stand things not level.

 

[dancinplumba]

Always fit them horizontally if possible, then they will work correctly

 

[Whyme]

Off level for air... I'm definately using that one..