two loop systems

Mark_42

My water heating boiler has two loop systems. one supplies heat for upstairs and the other for basement. One expansion tank is installed on the pipe for upstairs zone. the expanison tank is not installed on the main pipe (common pipe). that is to say, the expansion tank is not shared by the loop system for basement heating. Does the basement zone also need an expansion tank?

Mark Walnicki_2

expansion tank

Can the basement loop still "see" the expansion tank? Are there any flow-checks or zone valves in-between the basement loop and the expansion tank?

As a guess, without seeing it, you're probably okay, if the expansion tank were completely blocked from the basement zone, you would probably pop the relief when just the basement zone called for heat.

That being said, and again without seeing it, I would further guess this could be repiped and set up better. Is the system noisy? How is the heat delivery to the zones? What's the pressure gauge read?