Takagi T-D2-IN-NG Indoor Condensing Tankless Water Heater
Takagi T-D2-IN-NG Indoor Condensing Tankless Water Heater Review
The Takagi T-D2-IN-NG is an indoor condensing tankless water heater in the Takagi (Rheem-owned) line. The "T-D2" identifies the dual-flow condensing platform; "IN-NG" means indoor natural gas.
Specs: 199,000 BTU natural gas input, UEF 0.95 condensing, 10.0 GPM at a 35°F rise, dual stainless heat exchanger, PVC condensing venting. 15-year warranty on heat exchanger.
The T-D2 platform is Takagi's flagship dual-flow condensing tankless. Same engineering as Rheem RTGH series (Rheem acquired Takagi in 2009). Sold under both Takagi and Rheem badges through different channels.
About $1,800 unit, $3,500 installed. Right buyer: 3+ bath primary residence wanting Japanese tankless engineering through plumbing supply houses (Ferguson, Hajoca) where Takagi-branded units are commonly stocked.
- On-demand operation at 10 GPM — no standby heat loss; unlimited hot water if demand is within flow-rate capacity
- UEF 0.95 — top-tier efficiency; qualifies for Inflation Reduction Act §25C residential credit
- 15-year warranty — top-tier coverage for residential water heaters
- High 10 GPM output — serves 3+ simultaneous hot-water fixtures in most US climates
- Requires dedicated 199K BTU gas supply line — undersized gas piping is the leading cause of flow-rate shortfalls