Resideo EA79A1004 Air Vent R-410A The Aprilaire 4851 Relay is

The Aprilaire 4851 Relay is a high-performance Blower Activation Relay engineered specifically for seamless integration with whole-house humidification and HVAC systems

Calibrated to a -0

Replacing the power element is the standard procedure for restoring proper HVAC expansion valve modulation

Universal Replacement: Specifically engineered as the direct functional equivalent for the HH57AC076

Resideo EA79A1004 Air Vent R-410A The Aprilaire 4851 Relay isThe Resideo EA79A1004 Air Vent is a professional grade solution for purging air from high pressure mains and equipment in both hot and cold closed loop water systems. Designed with a heavy duty brass shell construction, this industrial grade automatic vent ensures quiet and efficient system operation by eliminating air pockets that cause airlock and noise. This 3 4" AutoAirVent W Shutoff includes a dual connection configuration with a 3 4 inch male