Unvented Expansion Vessel

[leakeee]

Hi

I went to a job to change a zone valve but noticed that the htg pressure vessel was on the flow after the zone valve.

The system has twin zones plus hot water , should i change it and put it on the return?

I know it will probably be fine but abit worried if they turn off all the rads and have the zone valves off. Should i reply on the

bypass for the expansion to go through the flow pipe.

I got my unvented ticket just thought i would ask for opinions,

Cheers

 

[buckley plumb]

before pump is best