Expansion position on zoned heating

[MethodPH]

Just wondering if anyone had any thoughts/ objections to position of expansion vessel. 3 zones on heating upstairs, downstairs and UFH. All zone valves on flow, pump on flow, loss header as well. Expansion vessel it situated on the return from the upstairs zone. I suppose it can’t be cut off by any means

 

[ShaunCorbs]

Fine and better to have it on the return tbh

ideally should be at the neutral point eg connected into the llh but it’s fine where it is

 

[SimonG]

Prefer it on the return, deals with lower temperatures then.

 

[SJB060685]

As above. Ideally you want the vessel on the return going back to boiler, with the pump shortly after it. This creates a positive pressure through the boiler and system back to thr neutral point where the vessel is tapped in and a short section between vessel and pump under negative pressure. This creates ideal pressure throughout the system as well as not exposing the vessel to high flow temperatures, which lead to early failure of the diaphragm.
With a low loss header you should tap in the vessel on the bottom of the header, this creates the neutral point, with positive pressure through boiler loop.