LP (liquid propane) tankless gas water heater, maximum 180,000 BTU (British thermal unit) or for 2 major appliances or 2 showers at a time. ENERGY STAR qualified. Indoor installation only. Scale reduction software, freeze protection, and multiple safety features. Weight 58lbs. Rated up to 10,100 feet elevation. Requires 3/4" gas line. Easy installation Schedule 40 PVC (polyvinyl chloride) venting system. High efficient condensing model. Energy factor: 0.95. Units must vent independently and with approved venting materials. Optional concentric vent kit available. 12 year limited warranty on heat exchanger. 5 year limited warranty on parts. Unit dimensions: 17.75" W x 11.25" D x 23.625" H. Tankless Water Heater Valve Set available, designed to simplify the installation, maintenance, and operation of tankless water heaters. Unit meets California Air Quality Management District Ultra-Low NOx rules. Not approved for mobile/manufactured home installation.