EcoSmart ECOS 27 vs Stiebel Eltron Tempra 36 Trend

Last updated: October 31, 2026

The Stiebel Eltron Tempra 36 Trend is the better tankless water heater overall, rated 4.1 to 3.3. The Stiebel Eltron Tempra 36 Trend leads on heating power, efficiency and warranty. The EcoSmart ECOS 27 costs $200 less ($549 vs $749).

EcoSmart ECOS 27 vs Stiebel Eltron Tempra 36 Trend

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?

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 weightStiebel Eltron Tempra 36 TrendEcoSmart ECOS 27
Overall rating4.1/53.3/5
Value 35%58 $20.81 per kW ($749, 36 kW)60 $20.33 per kW ($549, 27 kW)
Heating power 25%100 36 kW64 27 kW
Efficiency 15%100 0.98 UEF50 0.94 UEF
Warranty 25%57 7-year heat exchanger warranty29 5-year heat exchanger warranty

Specifications

Stiebel Eltron Tempra 36 TrendEcoSmart ECOS 27
Heating
FuelElectricElectric
Electric power36 kW27 kW
Max flow7.5 GPM6.6 GPM
UEF0.980.94
Installation
Voltage240 V240 V
Breakers150 A total120 A total
Weight19 lb10.9 lb
Features
Built-in recirculationNoNo
Wi-FiNoNo
Heat exchanger warranty7 years5 years
Parts warranty3 years1 year

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