Watts 0590721 Air Vent R-407C Veteran technicians recognize that a

Veteran technicians recognize that a functional compressor heater is the first line of defense against premature mechanical failure

if you are connecting both a wired controller and a DIII-Net adapter simultaneously

if the heat pump isn't heating at all

Built for counterclockwise (CCW) rotation

always verify the wiring diagram inside your specific ComPac unit

Watts 0590721 Air Vent R-407C Veteran technicians recognize that aThe Watts 0590721 FV 4M1 1 Air Vent is a high performance 1 inch automatic air vent valve designed for veteran contractors managing commercial and residential hydronic heating systems. Engineered with a rugged brass body construction, this vertical pattern vent facilitates the continuous removal of trapped air from both hot and cold water distribution lines, preventing air lock and system noise. It features a 150 PSI maximum pressure rating and a