Stiebel Tempra 29 Plus
Amazon customer rating as of
Tankless Geek editorial score: 4.4/5
The Tempra 29 Plus is Stiebel Eltron's most popular whole-house electric tankless — the German-made 28.8 kW model that hits the sweet spot between capacity and a realistic electrical install. It uses the same Advanced Flow Control that holds a constant set temperature under heavy demand, self-modulates power to flow, runs at 99% efficiency with zero standby loss, and offers a digital display with dial control from 86–125 °F. Like the rest of the line it carries a 7-year leakage / 3-year parts warranty and weighs just 19 lbs.
Its electrical needs are heavy but far more attainable than the 36 Plus: about 120 amps across three 40-amp double-pole breakers on three runs of 8-gauge wire, with a 200-amp service recommended. In warm climates it comfortably runs about three showers; in cooler regions, two to three bathrooms. Its max flow is roughly 5.6 GPM at a mild rise, tapering to about 2.8 GPM at a hard winter rise. With a large, strongly positive review base (~4.4 stars), owners and plumbers praise its steady temperature, quiet operation, and quality — with the recurring notes that the triple-breaker install takes planning and that very hard water can affect performance over time. For most whole-home electric buyers, this is the model to start with.
Key Features
Best Use Cases
Our Verdict
The whole-home electric tankless most buyers should look at first: enough capacity for a warm or moderate-climate house, with an electrical install that a 200-amp service can realistically support. Same German build and Advanced Flow Control as the 36 Plus, at a more attainable load. Just budget for three 40-amp circuits and a competent electrician.
Technical Specifications
| Power | 28.8 kW @ 240 V (21.6 kW @ 208 V), self-modulating |
|---|---|
| Electrical | ≈120 A · three 40 A double-pole breakers · 200 A service recommended |
| Max flow | Up to ~5.6 GPM at a mild rise |
| Temp control | 86–125 °F digital display + dial; Advanced Flow Control |
| Build | 99% efficient, zero standby loss; 19 lbs; 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) | 5.6 GPM |
| 45 °F | Mild climate (65 °F in → 110 °F) | 4.4 GPM |
| 60 °F | Cool climate (50 °F in → 110 °F) | 3.3 GPM |
| 70 °F | Cold climate (40 °F in → 110 °F) | 2.8 GPM |
Usable flow at a 110 °F target from 28.8 kW: kW × 3412 ÷ (ΔF × 500) — ≈5.6 GPM max at a mild rise, matching Stiebel/retailer ratings. Advanced Flow Control holds temperature by trimming flow under peak demand.
Pros
Cons
Buy it if…
- Whole-home use in warm to moderate climates
- Homes with 200 A service that can add three 40 A circuits
- Buyers wanting steady temperature and German build quality
- Those who found the 36 Plus's electrical needs impractical
Skip it if…
- Large homes in genuinely cold climates (step up to the 36 Plus)
- Panels that can't support ~120 A of added load
- Budget buyers — it's a premium unit
Installation Requirements
Professional vs DIY
The ~120 A load and 200 A service recommendation make an electrician and permit the right call.
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, 1480 ratings, as of 2026-09-13). These are owner opinions, not our own bench testing.
The large review base repeatedly credits Advanced Flow Control and self-modulation for steady temperature across multiple fixtures.
Owners note near-silent operation and appreciate the 99% efficiency with no standby loss compared to their old tank.
The three 40-amp double-pole breakers are the most-cited install challenge; a 200-amp service is recommended.
A minority in hard-water areas report flow or performance issues over time, underscoring the value of softening or maintenance.
Stiebel Tempra 29 Plus FAQ
What electrical does the Tempra 29 Plus require?+
About 120 amps — three 40-amp double-pole breakers on three runs of 8-gauge wire — with a 200-amp service recommended. It's the most-planned-for part of the install.
How many showers can it run?+
Roughly three showers in warm climates, or two to three bathrooms in cooler regions, thanks to Advanced Flow Control keeping temperature steady.
Should I get this or the 36 Plus?+
The 29 Plus suits most warm/moderate-climate whole-home installs on a 200-amp service. Choose the 36 Plus only for large, cold-climate homes with 300-amp service.
Does hard water affect it?+
It can. Some hard-water owners report reduced flow over time, so water softening or periodic maintenance helps preserve performance.
Product sources
Specifications verified 2026-09-13. Manufacturer documents are treated as the primary source for model specifications. Retailer pages are used only for customer ratings and owner-feedback themes.
- Tempra 29 Plus — Lowe's listing (5.62 GPM) (accessed 2026-09-13)
- Tempra 29 Plus — Home Depot reviews (accessed 2026-09-13)
- Tempra technical specifications (PDF) (accessed 2026-09-13)
Price range from leading retailers
* As an Amazon Associate, we earn from qualifying purchases
