Takagi T-K Jr tankless water heater is compatible with solar hot water systems, natural gas, and propane. This model provides radiant heat to small homes! Weighing in at 30lbs, this water heater measures 20.5" x 13.8" x 6.7" and starts with an electronic ignition and an AC 120 V power supply. Featuring 3/4" NPT water and gas connections, water pressure from 15 to 150 psi, this water heater requires a natural gas input or LPG input of 19,500 BTU to a maximum of 140,000 BTU. Natural gas pressure inlet minimum of 5" WC and maximum of 10.5" WC. LP gas pressure inlet minimum of 11" WC and maximum of 14" WC. Mainfold pressure for natural gas is 2.8" WC, and for propane 3.2" WC. ENERGY EFFECIENCY AND ENDLESS HOT WATER FOR THE SMALLER RESIDENCE