Takagi T-H3-DV-N Indoor Condensing Tankless Water Heater
Takagi T-H3-DV-N Indoor Condensing Tankless Water Heater Review
The Takagi T-H3-DV-N Indoor Condensing Tankless Water Heater is Takagi's flagship condensing residential tankless. 10.0 GPM peak flow, 199,000 BTU condensing burner, 0.95 UEF, 15-year heat exchanger warranty. Takagi is owned by AO Smith and competes in the value condensing-tankless segment — Takagi pricing typically runs $200–$400 below Rinnai/Navien flagships for comparable spec.
Headline specifications
- Type: indoor condensing tankless, natural gas (LP-convertible)
- Maximum flow rate: 10.0 GPM at 35°F rise
- BTU input: 15,000–199,000 BTU/h (modulating)
- Energy Factor (UEF): 0.95
- Min activation flow: 0.5 GPM
- Temperature range: 100°F – 140°F
- Warranty: 15-year heat exchanger, 5-year parts
- Venting: PVC/CPVC up to 65 ft
- Dimensions: 22" H × 14" W × 9" D (compact form factor)
Who this model is for
Value-conscious tankless buyers who want condensing-tier efficiency and 15-year warranty without paying Rinnai/Navien flagship prices. 3–4 person households with 1–2 bathrooms, existing natural gas service, install path for PVC venting. Buyers who don't need built-in WiFi.
Takagi shares AO Smith manufacturing depth and parts logistics — replacement parts are widely available in the AO Smith dealer network. For households committed to smart-home integration, Rinnai or Navien with built-in WiFi are better picks. For pure value tankless, Takagi.
Where the T-H3 beats the alternatives
Vs Rinnai RU199iN ($1,645): Takagi ~$300 less. Rinnai 11.1 GPM vs Takagi 10 GPM. Same warranty. Rinnai built-in WiFi; Takagi no WiFi. Takagi wins on price; Rinnai wins on flow and WiFi.
Vs Navien NPE-240A2 ($1,499): Takagi ~$200 less. Navien 11.2 GPM, ComfortFlow buffer, NaviLink WiFi. Takagi 10 GPM, no buffer, no WiFi. Navien clearly more feature-loaded; Takagi wins on absolute price.
Vs AO Smith ProLine Tankless 10 GPM ($1,449): same parent company. Takagi is the value-channel brand; AO Smith ProLine is the premium-channel brand. Hardware is functionally similar. Takagi ~$200 less; choose ProLine if your installer is AO Smith-distributor-specific.
Where it falls short
No built-in WiFi. In a 2026 market where competitors ship app integration standard at this tier, Takagi's purely mechanical control feels dated.
10.0 GPM trails Rinnai 11.1 and Navien 11.2 at the same-class tier.
Cold-water sandwich without buffer tank.
65 ft PVC vent run is shorter than the 100 ft on Rinnai/Navien/Bosch flagships — limits install location flexibility.
Takagi brand is lower-recognition than Rinnai, Navien, Rheem. Installer expertise varies — verify Takagi-certified or AO Smith-certified installer locally.
3/4" gas line, annual descaling required.
Install considerations
Verify 3/4" gas line capacity. PVC/CPVC vent up to 65 ft. 120V outlet. Service valves for descaling. Permit typical.
Install cost: $1,100–$2,000 like-for-like; $2,700–$4,300 tank-to-tankless conversion.
Maintenance
- Annual descaling required to maintain warranty
- Inlet filter clean annually
- Burner inspection every 3 years
Bottom line
The Takagi T-H3 is the value condensing tankless — 10 GPM, 0.95 UEF, 15-year warranty, $200–$400 below Rinnai/Navien flagships at comparable spec. Right pick for budget-conscious buyers who don't need WiFi and accept slightly lower peak flow. AO Smith parts logistics is a real advantage for parts/service. For premium feature set and full WiFi integration, step up to Rinnai RU199iN or Navien NPE-240A2.
- 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