Stiebel Eltron Tempra Plus 29 Tankless Water Heater
- 21.6/28.8 kW at 208/240 volts
- 3x50 circuit breaker size required, 3 x 8 wire
- 86 to 125F output, set by dial with digital display
- 150 psi working pressure
- No venting required, wall mount
- 7 years leakage, 3 years parts warranty
- Advanced Flow Control and self-modulating power
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A wall-hung electric tankless unit that holds a steady set temperature without venting. It needs heavy electrical service, so check panel capacity before planning the install, and note it is listed as discontinued.
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ASIN: B003QSGIAYModel: Tempra Plus 29Category: Water Heaters
Overview
Stiebel Eltron's Tempra Plus is an electric tankless water heater that mounts on the wall and heats water as it flows, with no tank and no vent to the outside. It senses flow and incoming temperature, then applies only the power needed to reach the temperature set on its dial.
Temperature stability is the strength here: self-modulating power and flow control adjust as demand changes, so a shower does not swing hot and cold. The limit is electrical, because the unit draws on several large breakers that an older panel may not have room for. Flow capacity is not stated, so sizing it to a household is guesswork from this page.
Who it's for
Owners of homes with ample electrical service and no easy vent path will use its slim wall-mount body well. Houses on smaller panels, or buyers who need a stated flow rate for a large family, should look elsewhere.
Pros and cons
- No venting to the outside
- Self-modulating power holds set temperature
- Digital display with dial selector
- Slim wall-mount body
- Needs multiple large breakers and heavy wire
- Flow rate not listed
- Listed as a discontinued model
- Specs give conflicting voltage figures
Performance notes
Output temperature is governed by the electronics, which read flow and incoming temperature and apply just enough power to reach the dial setting. Advanced Flow Control adjusts the water flow when demand outruns the heating power, giving up some pressure to hold a steady temperature. Colder incoming water raises the power needed, so the same set point delivers less flow then.
Specifications
| Brand | Stiebel Eltron |
|---|---|
| Model | Tempra Plus 29 |
Frequently asked questions
Can the Tempra 29 Plus run on an ordinary household circuit?
No. It draws 3x35/3x40 amperage and calls for a 3x50 minimum breaker size with 3 x 8 recommended wire. Have an electrician confirm your panel can carry it.
Will the Tempra 29 Plus hold temperature when several taps run?
Advanced Flow Control adjusts the water flow to hold the set temperature as demand rises, so flow may drop instead of temperature.