In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
ZC ZR and beyond on TACO SR506 exp for primary pump
Trying to come to grips with a system that we set up primary secondary to limit the problems with low return temps on a Weil McClain Gold hydronic boiler.
There are 4 zones, actually on a SR506 exp but I assume the question is relevant to anything in the SR50x series.
I assumed that once you had the PC70x running through the plug in expansion that I could remove the tab linking ZC and ZR and one would give me 120 when any zone was calling, and the other would give me 120 when there was a fire demand to the boiler. Because you want the primary pump running anytime any one of the secondary pumps is running, even if the boiler is made on temp.
In the old days this all would have been handled between the relay and the boiler, but now with the relay acting as temp reg. for the boiler as well, where do I tap for a primary pump?
My current solution is to go over to a Tekmar 256 downstream of the SR 506 which then just makes it unfortunately redundant that I bought the exp. I should have saved the dough for the downpayment on the 501 I'll need to run the boiler independent of the 256 when the priority circuit calls and I have to jump to the background limits on the boiler to get the temps to make hot water.
Am I missing a contact on the SR506 I could be using, or could I relatively easily tap the circuit board to pick up a demand signal that isn't overridden by the expansion reset controller.