Takagi T-KJr2-IN-NG Compact Tankless Water Heater

The Takagi T-KJr2-IN-NG is a compact natural gas tankless water heater rated at 140,000 BTU — smaller than the 199K BTU residential premium class. "T-KJr2" identifies it as the Junior 2nd generation (sized below Takagi's larger T-K4 and T-H series), "IN" means indoor-rated, "NG" is natural gas. Common in smaller homes (1–2 bathrooms) and apartments where the higher-BTU units are oversized for the demand.

Specs: 140K BTU input, UEF 0.83 (non-condensing), 6.6 GPM peak at a 35°F rise or 3.3 GPM at a 70°F rise. Single 1/2" gas connection (where 199K BTU units require 3/4"), 4-inch Category III stainless B-vent. The smaller gas line requirement is meaningful — many homes can install the T-KJr2 without the gas-line upsize work that larger tankless units demand.

Now part of the Rheem catalog (Takagi acquired by Rheem in 2009) but still sold as Takagi-branded through specific channels. Service support via Rheem's network. 10-year warranty on the heat exchanger, 5-year on parts.

Right buyer: 1-bathroom home or small 2-bath home in warm climates, particularly when existing gas line is 1/2" and avoiding upsize costs matters. Wrong buyer: 3+ bathroom homes or cold-climate primary residences (capacity insufficient). About $1,000 unit, $2,200 installed.