Head-to-head · Best Tankless Water Heaters

Stiebel Eltron Tempra 36 Plus 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

Stiebel Eltron Tempra 36 Plus comes out ahead by a narrow margin (4.4 vs 4.3). The gap is mostly about All-electric homes in moderate climates that need whole-house hot water without gas or venting. — read the strengths below before deciding.

Higher ratedRanked #2 in Best Tankless Water Heaters

Stiebel Eltron Tempra 36 Plus

4.4

$789.11as of Jun 7

The Stiebel Eltron Tempra 36 Plus is the clear frontrunner for whole-home electric tankless heating, delivering up to 7.5 GPM from its 36 kW heating element. This Old House rated the Stiebel Eltron electric line 4.4/5, and Bob Vila named it best electric, both praising its silent operation and standout Advanced Flow Control, which dynamically reduces flow rather than letting cold-water sandwiching occur when demand exceeds capacity. It needs serious electrical service and performs best in moderate climates, but for an all-electric home it is the top whole-house pick.

Strengths

— Best whole-home electric option, up to 7.5 GPM at 36 kW
— Advanced Flow Control throttles flow to prevent cold-water sandwiching
— Silent operation with no combustion, venting, or CO risk

Watch-outs

— Needs substantial electrical service — often a panel upgrade
— Flow rate drops in cold climates with high temperature rise
— No federal gas tax credit (electric)

$789.11 · Check Price on Amazon Full review →

Ranked #3 in Best Tankless Water Heaters

Takagi T-H3-DV-N

4.3

$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 Amazon Full review →

How they stack up

Stiebel Eltron Tempra 36 Plus

The Stiebel Eltron Tempra 36 Plus is the best whole-home electric unit, with a 7.5 GPM flow rate that beats the EcoSmart ECO 27 and Rheem RTEX-13 but trails the gas Rinnai RU199iN and Takagi T-H3-DV-N. Its Advanced Flow Control is a feature neither the EcoSmart nor the Rheem offers, trading a brief flow reduction for consistently hot water.

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

Spec	Stiebel Eltron Tempra 36 Plus	Takagi T-H3-DV-N
Fuel	Electric	Natural gas
Power	36 kW	—
Flow Rate	Up to 7.5 GPM	Up to 10 GPM
Control	Advanced Flow Control + self-modulating	—
Voltage	240/208V	—
Venting	None required	—
Mounting	Wall-mounted	—
Origin	Made in Germany	—
Type	—	Condensing, Ultra-Low NOx
BTU	—	15,000 - 199,000
UEF	—	0.93
Heat Exchanger	—	Commercial-grade copper alloy
Installation	—	Indoor, direct vent
Use	—	DHW, recirculation, space heating

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