In 2010, Takagi released the T-KJr2-OS and T-KJr2-IN, two of the smallest water heaters in Takagi’s tankless water heater collection. Powerful yet compact, this unit with gas inputs as much as 140,000 BTUs per hour, which adequately meets the needs of most small American homes with up to two bathrooms. The wall-mounted T-K Jr. tankless water heater is specially designed to do everything that a forty-gallon tank-style water heater is capable of and more. This water heater can support radiant floor-heating applications as well as hydronic baseboard heating while providing domestic hot water for your plumbing needs. With an energy factor of 0.81-0.83, this unit provides around 228 gallons per hour in warm regions, and around 174 gallons per hour where input temperatures are below 40 degrees Fahrenheit.