Rheem Ecosense 8.4 GPM 180,000 BTU Natural Gas Mid Efficiency Indoor Tankless Water Heater A 8.4 GPM tankless water heater at a 35 degree temperature rise can provide enough hot water to supply a 2-3 bathroom home. 12-year limited warranty on heat exchanger and 5-year limited warranty on parts. Remote digital display shows precise temperature setting and maintenance codes. Requires 3"/5" category III concentric stainless steel or manufacturer listed and approved venting material. Model #ECO180DVN3