Stiebel Eltron Tempra 36 Trend
#2 in ElectricFull review
The pick for a larger home with 300 A service that wants electric whole house hot water, even in cooler regions. Few electric heaters match its power and warranty.
Amazon $749$749
The Stiebel Eltron Tempra 36 Trend is the better tankless water heater overall, rated 4.1 to 3.0. The Stiebel Eltron Tempra 36 Trend leads on heating power, efficiency and warranty. The Rheem RTEX-24 costs $200 less ($549 vs $749).
Rheem RTEX-24
#12 in ElectricFull review
A mainstream whole home heater for a two bathroom house in a warm climate. The Stiebel Tempra 24 Trend costs about the same with a longer warranty.
Amazon $549$549
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Stiebel Eltron Tempra 36 Trend for heating power (36 kW vs 24 kW), efficiency (0.98 UEF vs 0.93 UEF) and warranty (7-year heat exchanger warranty vs 5-year heat exchanger warranty).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every electric tankless water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Stiebel Eltron Tempra 36 Trend | Rheem RTEX-24 |
|---|---|---|
| Overall rating | 4.1/5 | 3.0/5 |
| Value 35% | 58 $20.81 per kW ($749, 36 kW) | 51 $22.88 per kW ($549, 24 kW) |
| Heating power 25% | 100 36 kW | 52 24 kW |
| Efficiency 15% | 100 0.98 UEF | 38 0.93 UEF |
| Warranty 25% | 57 7-year heat exchanger warranty | 29 5-year heat exchanger warranty |
Specifications
| Stiebel Eltron Tempra 36 Trend | Rheem RTEX-24 | |
|---|---|---|
| Heating | ||
| Fuel | Electric | Electric |
| Electric power | 36 kW | 24 kW |
| Max flow | 7.5 GPM | 5.9 GPM |
| UEF | 0.98 | 0.93 |
| Installation | ||
| Voltage | 240 V | 240 V |
| Breakers | 150 A total | 120 A total |
| Weight | 19 lb | - |
| Features | ||
| Built-in recirculation | No | No |
| Wi-Fi | No | No |
| Heat exchanger warranty | 7 years | 5 years |
| Parts warranty | 3 years | 1 year |