Takagi T-H3-OS-N Outdoor Condensing Tankless Water Heater
Takagi T-H3-OS-N Outdoor Condensing Tankless Water Heater Review
The Takagi T-H3-OS-N is an outdoor condensing tankless water heater in the Takagi (Rheem-owned) line. "T-H3" identifies the 199K BTU condensing model; "OS-N" means outdoor sealed natural gas.
Specs: 199,000 BTU natural gas input, UEF 0.95 condensing, 9.8 GPM at a 35°F rise, dual stainless heat exchanger. Sealed direct-vent exterior mounting. 15-year warranty on heat exchanger.
The outdoor configuration is common in warm-climate markets where exterior mounting is code-acceptable. Eliminates indoor venting cost and frees indoor space.
About $2,200 unit, $3,400 installed. Right buyer: warm-climate primary residence with suitable exterior wall mount location, particularly retrofit replacements where eliminating indoor venting saves significant install cost.
Takagi is fully integrated into Rheem's service network — service through any Rheem plumber, parts at Home Depot pro counter.
- Outdoor mounting — eliminates indoor venting cost ($500–1,500 savings) and frees mechanical room space
- Strong UEF 0.94 efficiency — approximately 20% lower annual operating cost vs 0.62 standard
- 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