this harness will provide the necessary power and feedback loop integration

the standard mounting footprint and screw terminal connections facilitate a streamlined HVAC contactor replacement process in the field

Proper installation requires inspecting the pump gaskets and checking the electrical terminal box orientation for terminal block clearance

Durable Construction: Lightweight yet rugged aluminum housing provides long-lasting service in industrial settings

Is the EP2121S compatible with legacy EP2121S1 installations

Resideo HPSR104 Switching Relay L99H008 this harness will provide theThe Resideo HPSR104 is a robust four zone switching relay designed for professional hydronic applications. This 120V pump zoning panel provides precise control for up to four circulator pumps, integrating a dedicated priority zone for domestic hot water (DHW) calls. Engineered for versatility, it is fully compatible with most thermostats, including power stealing, electromechanical, and modern smart thermostats like the T6 Pro. Each thermostat