Hey all,

I'm replacing a controller on a residential geothermal system with the HBX eco-600. The CD and HD terminals have two dry contacts each but the diagram shows that I can connect the Y and W to one side of each terminal where I have 24VAC coming from the t-stat. That doesn't trigger demand on the controller but jumping the two does (dry contact). I have 120 VAC connected to the board so I'm assuming it is picking up the common from that, any suggestions before I install two relays to give me a dry input?

Also, do most residential systems skip the controller and just use an aquastat with the tank with the Air handler connected directly to the t-stat?

Thanks in Advance