Tankless Under Sink Water Heater - Brand New. I installed it before I realized that I had a 15A circuit under the sink. The unit requires a dedicated 30A circuit. I was not able to return the unit to the plumbing supplier. It was installed for 10 minutes and then reboxed. Very small and mounts either right side up or upside down. Standard ⅜” fittings. Endless warm water for washing. 7 ½” x 5 ⅝” x 3 ¼”