What it delivers
The Rheem RETEX-36 Electric Tankless Water Heater is a whole-house electric tankless rated at 36 kW.
At a 45°F rise (mild inlet water to a 120°F set point) it holds about 5.5 GPM, 2 showers at 2 GPM; in winter, at a 70°F rise, about 3.5 GPM, 1 shower at 2 GPM. Size it to your fixtures.
At 240 volts 36 kW is about 150 amps. The requirement calculator shows it at 208 V too; an electrician confirms the panel. On its own it takes more than 60% of a 200-amp service.
Electric tankless units need no venting and no gas, and work best where inlet water stays mild, because every degree of rise costs flow.
From the listing: features: Digital Thermostatic Temperature Controls, UEF up to.94; model: RETEX-36.
The listing gives dimensions of 21.62 in (W) x 18.25 in (H), a weight of 19 lb and 683089 8 GPM elec tnklss in the box.
Right unit for this house?
Install it when
- 2 showers at once 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
- 36 kW
- No venting or gas line
Trade-offs
- Draws about 150 A
- Winter flow is much lower
- Breaker needs not stated
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 | RETEX-36 | Retailer |
|---|---|---|
| Dimensions (seller) | 21.62"W x 18.25"H | Retailer |
| Features (seller) | Digital Thermostatic Temperature Controls, UEF up to .94 | Retailer |
| Power | 36 kW | Retailer |
| Product weight | 19 lb | Retailer |
Rival units at this flow
More electric tankless water heaters rated for similar demand
- Stiebel Eltron DHC 12/15-2 Trend 12 kW Electric Tankless Water Heater
- LiberLive REK11/13 11 kW Electric Tankless Water Heater
- Camplux TEW11-CA 11 kW Electric Tankless Water Heater
- Ranein RE13K 13 kW Electric Tankless Water Heater
Full electric tankless water heaters spec grid · Every Rheem unit in the catalog
Final verdict
A solid whole-house electric tankless for 2 showers at once in mild climates.
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