UR Heated Wells are models that are recognized as components to be used in someone else’s appliance. The customer that buys these models is responsible to seek UL approval of the larger appliance that includes Hatco UR components. Typically, UR units do not have conduit to protect wires or an enclosure to isolate the controls. UR units are commonly purchased by fabricators. Hatco uses a two letter suffix used to identify UR (Underwriter Laboratories Recognized) units. RT and RN do not stand for Remote Thermostat and Remote Infinite Switch. Instead, they stand for Recognized, with Thermostat and Recognized with Infinite Switch, respectively. All HWBs have remote controls.