2 port valve zones piping

[henry1]

When piping 2 heating zones, each controlled by a 2 port valve, do you run a return pipe for each zone or can the 2 zones share one, especially if the return pipe for one zone is near the rads for the other zone?

My guess is that they should be separate to prevent heat convection within the return pipework heating the other zone.

 

[ReJect]

The 2 zones can share a return.
Just have to be careful how you pipe it.
You only do one tee off and also consider any pipes that heat could convect through.
In other words, you don’t tee off to rads a few times or that part of circuit will loop through when the other circuit is working.
Hope that makes sense as difficult to explain?

 

[fezster]

Ensure your hw cylinder (if you have one) return is the last tee to prevent reverse circulation.