Stiebel Eltron Tempra 36 Plus
Amazon customer rating as of
Tankless Geek editorial score: 4.5/5
The Tempra 36 Plus is the top of Stiebel Eltron's whole-house electric line — a German-made 36 kW unit built for the hardest job in electric tankless: whole-home hot water in a genuinely cold climate. Its Advanced Flow Control automatically throttles flow a touch to hold your set temperature when demand outruns capacity, so you never get a cold surprise mid-shower, and it runs at 99% efficiency with zero standby loss, a digital display, and dial temperature control. It's backed by Stiebel's 7-year leakage / 3-year parts warranty.
The catch is electrical, and it's a big one: 36 kW draws about 150 amps across three 50-amp double-pole breakers, and Stiebel recommends a minimum 300-amp service. That rules out most existing homes without a service upgrade. In return you get real cold-climate capacity — roughly 7 GPM at a mild rise, and a still-usable ~3.5 GPM at a hard 70 °F winter rise, where lesser electric units collapse to a trickle. Owners and professional installers rate it highly (~4.4 stars) for rock-steady temperature and build quality. It's overkill for a warm climate or a modest panel — but for a large cold-climate home with the electrical service to feed it, it's the electric unit that actually keeps up.
Key Features
Best Use Cases
Our Verdict
The electric tankless for the hardest case: a large home in a cold climate with the electrical service to match. Advanced Flow Control and 36 kW deliver steady whole-home hot water where lesser units fail — but the ~150 A draw and 300 A recommended service put it out of reach for most existing panels. Right unit, demanding prerequisites.
Technical Specifications
| Power | 36 kW @ 240 V (27 kW @ 208 V), self-modulating |
|---|---|
| Electrical | ≈150 A · three 50 A double-pole breakers · 300 A service recommended |
| Max flow | Up to ~7 GPM at a mild rise |
| Temp control | Digital display + dial; Advanced Flow Control |
| Dimensions | 16.5 × 14.25 × 4.5 in; 3/4" NPT; made in Germany |
| Warranty | 7-yr leakage / 3-yr parts |
Specifications verified against the linked source documents. See Sources below.
How much hot water you'll actually get
Usable flow drops as incoming water gets colder. Figures are calculated from rated output (kW) and labeled as such — not bench-tested by us.
| Temperature rise | Typical scenario | Usable flow |
|---|---|---|
| 35 °F | Warm climate (75 °F in → 110 °F) | 7 GPM |
| 45 °F | Mild climate (65 °F in → 110 °F) | 5.5 GPM |
| 60 °F | Cool climate (50 °F in → 110 °F) | 4.1 GPM |
| 70 °F | Cold climate (40 °F in → 110 °F) | 3.5 GPM |
Usable flow at a 110 °F target from 36 kW: kW × 3412 ÷ (ΔF × 500). Matches Stiebel's own figures (≈4.5 GPM at a 55 °F rise). Advanced Flow Control trims flow slightly to hold temperature under peak demand.
Pros
Cons
Buy it if…
- Large cold-climate homes needing true whole-house electric hot water
- Homes with 300 A service (or planning the upgrade)
- Buyers who want steady temperature under heavy simultaneous demand
- Those prioritizing German build quality and a strong warranty
Skip it if…
- Homes without the electrical service for a ~150 A load
- Warm-climate or modest-demand homes (a smaller Tempra fits better)
- Budget buyers — this is a premium, high-capacity unit
Installation Requirements
Professional vs DIY
At ~150 A with a 300 A service recommendation, this is firmly an electrician-and-permit job; the panel assessment comes before anything else.
Gas and electrical work should be done by a licensed professional, and most installs require a permit and must meet local building codes — DIY work can void the manufacturer warranty. Always confirm the unit's own manual for exact clearances, venting, and sizing.
What owners report
Themes summarized from retailer customer feedback (4.4/5 Amazon customer rating, 800 ratings, as of 2026-08-23). These are owner opinions, not our own bench testing.
Owners repeatedly praise Advanced Flow Control for holding a constant temperature even with multiple fixtures running.
Professional installers and repeat Stiebel owners rate the German build and reliability among the best in electric tankless.
The three 50-amp circuits and 300-amp service recommendation are the hardest part of the install to plan and pay for.
Unlike smaller electric units, owners in cold regions report it genuinely keeps up with whole-home demand.
Stiebel Eltron Tempra 36 Plus FAQ
What electrical service does the Tempra 36 Plus need?+
About 150 amps across three 50-amp double-pole breakers, with a 300-amp service recommended. Most existing homes need a service upgrade — confirm with an electrician first.
How is it different from the Tempra 29 Plus?+
It's the higher-capacity model (36 kW vs 28.8 kW) for larger, colder-climate homes — but it demands markedly more electrical service. Many homes are better served by the 29 Plus.
Will it work in a cold climate?+
Yes — that's its purpose. It delivers roughly 3.5 GPM even at a hard 70 °F winter rise, where smaller electric units fall short.
What does Advanced Flow Control do?+
It automatically reduces flow slightly when demand exceeds capacity, so output temperature stays constant instead of turning cold.
Product sources
Specifications verified 2026-08-23. Manufacturer documents are treated as the primary source for model specifications. Retailer pages are used only for customer ratings and owner-feedback themes.
- Tempra 36 Plus — Stiebel Eltron / PexUniverse specs (accessed 2026-08-23)
- Tempra 36 Plus — Lowe's listing (accessed 2026-08-23)
- Tempra technical specifications (PDF) (accessed 2026-08-23)
Price range from leading retailers
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