Welcome to the New Keller Supply Website - Our new website is now live. Enjoy improved product search, enhanced navigation, and an upgraded online experience. We welcome your feedback as you explore the new site.
The REU-OPU3 is a normally Open (NO) or Normally Closed (NC) switch. This switch connects to the PC Board in the Rinnai Tankless Water Heater or Boiler to act as: Domestic priority control for combination domestic hot water / hydronic air handler applications. Maintenance indicator to work in conjunction with a Building Management System (BMS) to provide system monitoring.