What it delivers
The Stiebel Eltron Tempra 29 Plus 28.8 kW Electric Tankless Water Heater is a whole-house electric tankless rated at 28.8 kW on 240 volts. Its listing gives a maximum flow of 3.0 GPM.
Expect about 2.8 GPM with cold winter water (a 70°F rise) and 3.0 GPM when the inlet is milder (45°F rise); that is 1 shower at 2 GPM in January. Try your own inlet temperature.
At 240 volts 28.8 kW is about 120 amps. The maker calls for 3 separate dedicated 40 amp breakers. The requirement calculator shows it at 208 V too; an electrician confirms the panel.
It skips venting entirely, but the amps are the hurdle: check the panel before the plumbing.
Listed details: features: LED Display; material: Copper; model: Tempra 29 Plus.
The listing gives dimensions of 16.63 in (W) x 14.5 in (H) and a weight of 19 lb.
Right unit for this house?
Install it when
- One shower at a time in mild climates
- Homes with no gas service
Look at another unit when
- Panels without spare capacity
- More than 1 shower at once in cold winters
Strengths and trade-offs
Strengths
- 28.8 kW
- Up to 3.0 GPM
- No venting or gas line
- Breakers stated by the maker
Trade-offs
- Draws about 120 A
- Weak at a large winter rise
Install limits
- Figures are the maker's or seller's own. Flow at a rise is our estimate from the input; gas, venting and electrical work needs a licensed professional.
Rated performance
Every figure below comes from the source shown in brackets. Where the maker doesn't state something, we say so instead of estimating.
| Model number | Tempra 29 Plus | Retailer |
|---|---|---|
| Dimensions (seller) | 16.63"W x 14.5"H | Retailer |
| Features (seller) | LED Display | Retailer |
| Power | 28.8 kW | Retailer |
| Voltage | 240 V | Retailer |
| Max flow (maker) | 3 GPM | Retailer |
| Product weight | 19 lb | Retailer |
| Material | Copper | Retailer |
| Breakers (maker) | 3 separate dedicated 40 amp breakers | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- WINTEMP WM36V 36 kW Electric Tankless Water Heater
- Eemax EEM24036 36 kW Electric Tankless Water Heater
- Eemax HA036240 36 kW Electric Tankless Water Heater
- Rheem RETEX-36 Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every Stiebel Eltron unit in the catalog
Final verdict
A well-specified whole-house electric tankless for one shower at a time in mild climates.
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