The all new T-K4 models have an impresive max GPM of 8.0GPM. This Tankless Water Heater adds 1 more shower over the Takagi T-KJr2 at minimal increase in cost and is perfect for domestic hot water as well as hydronic/radiant heating applications in mid size residential homes or apartments with 2-3 bathrooms.PropaneOutdoor installation only11000 ~ 190000 BTU/hr0.82 energy factor8.0 GPM max flow rateExhaust & Water Temperature Safety ControlNOTE: All water heaters of any type MUST be installed by a trained and licensed technician. Failure to do so may result in damage injury or death. Warranties may be void if installed by non-licensed personnel. We will not be held liable for any damages injury or death caused by proper or improper installation of hot water heaters. We will not be held liable for any local state county or city code violations caused by the improper selection of water heaters.[]