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Head-to-head · Best Tankless Water Heaters

Rinnai RU199iN vs Takagi T-H3-DV-N

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Rinnai RU199iN comes out ahead by a narrow margin (4.5 vs 4.3). The gap is mostly about Large households with gas service that need whole-home hot water for multiple bathrooms at once. — read the strengths below before deciding.

Rinnai RU199iN
Higher ratedRanked #1 in Best Tankless Water Heaters
Rinnai RU199iN
$1,177.78as of Jun 7

The Rinnai RU199iN is the best overall gas tankless water heater for whole-home use, delivering up to 11 GPM and 199,000 BTU — enough hot water for up to five appliances or a 3-4 bathroom house running simultaneously. Bob Vila named the Rinnai SENSEI line its best overall, and reviewers consistently praise the condensing efficiency (0.95 UEF, which qualifies for the federal tax credit) and Wi-Fi control. It is the priciest pick and needs gas service and condensing venting, but for a busy household in any climate, nothing here matches its capacity.

Strengths
  • — Industry-leading 11 GPM flow rate handles a 3-4 bathroom home at once
  • — Condensing design with a 0.95 UEF qualifies for the 30% federal tax credit
  • — 199,000 BTU output keeps up even in cold inlet climates
Watch-outs
  • — Highest upfront and installation cost of the group
  • — Requires gas service and proper condensing venting
  • — Overkill for a small home or apartment
$1,177.78 · Check Price on AmazonFull review →
Takagi T-H3-DV-N
Ranked #3 in Best Tankless Water Heaters
Takagi T-H3-DV-N
$1,500as of Jun 7

The Takagi T-H3-DV-N is Bob Vila's best condensing gas pick — a 10 GPM, 199,000 BTU unit built with a commercial-grade copper-alloy heat exchanger that suits heavier residential use like recirculation or space heating. It's Ultra-Low NOx compliant, important in strict-emission states, and Bob Vila praised that it 'provides plenty of heating power for most households.' Its 0.93 UEF trails the Rinnai RU199iN slightly and it lacks the Rinnai's smart-app polish, but as a rugged, high-capacity condensing gas heater it's an excellent whole-home choice.

Strengths
  • — Condensing gas design delivering up to 10 GPM
  • — 199,000 BTU handles most whole-home demand
  • — Commercial-grade copper-alloy heat exchanger for heavy use
Watch-outs
  • — Slightly lower UEF (0.93) than the Rinnai RU199iN
  • — Requires gas service and condensing venting
  • — Professional installation needed
$1,500 · Check Price on AmazonFull review →

How they stack up

Rinnai RU199iN

The Rinnai RU199iN is the highest-capacity unit here, with an 11 GPM gas flow rate that dwarfs the electric Stiebel Eltron Tempra 36 Plus (7.5 GPM), EcoSmart ECO 27, and Rheem RTEX-13. Only the gas Takagi T-H3-DV-N approaches it, and the RU199iN edges it on UEF efficiency. It costs the most upfront and, unlike the electric units, requires gas and condensing venting.

Takagi T-H3-DV-N

The Takagi T-H3-DV-N is the second gas unit here, matching much of the Rinnai RU199iN's 199,000 BTU output at a slightly lower 10 GPM and 0.93 UEF. Like the Rinnai it far outflows the electric Stiebel Eltron Tempra 36 Plus, EcoSmart ECO 27, and Rheem RTEX-13, but it offers fewer smart features than the Wi-Fi-equipped Rinnai.

Specs side-by-side

SpecRinnai RU199iNTakagi T-H3-DV-N
FuelNatural gasNatural gas
TypeCondensingCondensing, Ultra-Low NOx
Flow RateUp to 11 GPMUp to 10 GPM
BTU15,000 - 199,00015,000 - 199,000
UEF0.950.93
ConnectivityWi-Fi (Rinnai app)—
InstallationIndoorIndoor, direct vent
Tax CreditQualifies (UEF 0.95+)—
Heat Exchanger—Commercial-grade copper alloy
Use—DHW, recirculation, space heating
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