I am wiring my radiant heat system now. The system is a "homerun" system with a primary circut and 3 secondary circuits, each with their own circulator and thermostat.
The boiler is a high efficiency weil-McClain. It can control up to 3 circulators. Because my set-up has 4 circulators, I have a Taco 503 switch relay to control the 3 circulators for each zone, and pair each up to the appropriate thermostat control (one for each floor of the house).
The problem is that I'm not totally certain how to connec the switch relay to the boiler's controller. There are leads "X1" and "X2" near where the 120VAC input is. On the wiring diagrams, these are meant to attach to the "TT aquastat controls". The boiler input from any source must be a dry contact (like from a thermostat).
I've wired these leads to the boiler controller assuming they are dry contacts. However, I'm not sure this is correct and don't want to fry the system. Anyone have any experience with this?
Also, does anyone know if I can use the 24 VAC leads on the TACO 503 to power an i-series 4-way mixing valve?