Stiebel Eltron Tempra Plus Series Tankless Water Heaters

The Stiebel Eltron Tempra Plus Series electric tankless water heaters are the most sophisticated thermostatically-controlled on demand, instantaneous water heaters available on the market today.

Stiebel Eltron offers Tempra Plus models ranging from 12 to 36 KW in power. Each Tempra Plus model features Stiebel Eltron's advanced microprocessor technology which constantly monitors the water flow rate and incoming water temperature and adjusts the power level to maintain a precise output temperature as selected by the user.

The Tempra Plus series models take temperature control to another level, offering the industry's only Advanced Flow Control technology. This technology automatically adjusts the flow of water when the unit's sensor's detect that the flow demand is exceeding the heater's capacity. This feature is particularly useful in cold climates and other applications where the electrical service size does not permit the installation of a larger model where it may be desirable to handle occasional high flow demands. It is also desirable where high output temperatures are required for temperature-critical applications (commercial dishwashers, etc.) where flow rates are not always predictable.

A simple adjustment dial on the front of the heater allows you to set the output water temperature to whatever temperature you desire between 86 and 140F (30 to 60C)[Note, maximum temperature setting on some models is 125F (52C)]. To learn more about what makes Stiebel Eltron tankless heaters superior to its competition, visit our comparison of tankless water heater technologies page.

Selecting a model for your application is largely dependent on your incoming water temperature, flow rate requirements, and what features you desire. Please view our Tankless Water Heater Model Selector Page for proper sizing information. The specifications of each Stiebel Eltron tankless water heater model is noted in the chart below - click on the name of the heater for more details.

Stiebel Eltron Tempra Plus Series Specifications

Tempra 36 Plus Tempra 29 Plus Tempra 24 Plus Tempra 20 Plus Tempra 15 Plus Tempra 12 Plus
Application Extreme North and/or Very High Flow Rates Northern Regions or High Flow Rates Northern USA or Higher Flow Rates Southern USA / Moderate Flow Rates Tropical /
Tropical /
Temp Control Full micro-processor-based thermostatic temperature control featuring digital temperature selector /
display and full power modulation based on flow rate and incoming water temperature. Dynamic Advanced Flow Control Technology - adjusts the flow of water when the unit's sensor's detect that the flow demand is exceeding the heater's capacity.
Digital Temp. Setting Display Yes
Hinged Case Yes
(KW's @ 240v)
36 KW 28.8 KW 24 KW 19.2 KW 14.4 KW 12 KW
(KW's @ 208v)
27 KW 21.6 KW 18 KW 14.4 KW 10.8 KW 9 KW
Max Temp Rise
@ 1.5 GPM
240v (208v)
92 F (92F) 92 F (92F) 92 F (82F) 88 F (66F) 65 F (49F) 54 F (41F)
Max Temp Rise
@ 2.25 GPM
240v (208v)
92 F (82F) 87 F (66F) 73 F (54F) 58 F (44F) 43 F (37F) 36 F (27F)
Max Temp Rise
@ 3.0 GPM
240v (208v)
82 F (61F) 66 F (49F) 54 F (41F) 44 F (33F) 33 F (25F) 27 F (20F)
Max Temp Rise
@ 4.0 GPM
240v (208v)
55 F (41F) 44 F (33F) 37 F (27F) 29 F (22F) not recommended
Max. Output Temperature The maximum output temperature is a function of incoming water temperature and water flow rate. For residential applications, all units are factory pre-set to permit a temperature setting from 86F (30C) to 140F (60C). The temperature setting can be easily adjusted using the adjustment dial on the front of the heater.
Heating Modules 3 2 1
Dimensions 16.6" x 14.5" x 4.6" (55.2 x 36.7 x 11.6cm)
Weight 17.6 lbs (8.6kg) 15.4 lbs (7.3kg) 13.2 lbs (6.1kg)
Energy Efficiency 99%+ energy efficient
Activation Flow Rate 0.77 GPM / 2.9 LPM 0.50 GPM / 1.9 LPM 0.37 GPM / 1.4 LPM
Pipe Fittings 3/4" NPT
Working Pressure Max. Recommended Pressure = 150 psi (10 bar) - tested to 300 psi (20 bar).
Maximum recommended input temperature 107F (42C).
Voltage Requirements 208 - 240 volts / single phase / 50 - 60 Hz
Max. Amps
(@ 240 volts)
150 Amps 120 Amps 100 Amps 80 Amps 60 Amps 50 Amps
Max. Amps
(@ 208 volts)
132 Amps 105 Amps 88 Amps 70 Amps 52 Amps 44 Amps
Breakers Recommended* 3 x 50 Amp 3 x 40 Amp 2 x 50 Amp 2 x 40 Amp 2 x 30 Amp 1 x 50 Amp
Minimum amps to home 300 Amps 200 Amps 150 Amps 125 Amps 100 Amps
Recommended Wiring*
(AWG Copper)
3 x #8 3 x #8 2 x #8 2 x #8 2 x #10 1 x #8
Safety ETL Listed (USA and Canada)
Independently tested to comply with both US and Canadian safety standards
including ANSI/UL499 and CSA-E335-1/3E-94

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Stiebel Eltron
Tempra 36 Plus
Stiebel Eltron
Tempra 29 Plus
Stiebel Eltron
Tempra 24 Plus
Stiebel Eltron
Tempra 20 Plus
Stiebel Eltron
Tempra 15 Plus
Stiebel Eltron
Tempra 12 Plus

* Breaker size and wire gauge must meet all applicable local, state, provincial, and national electrical codes for your area - these are only guidelines that will apply to most installations. Some codes require use of electrical sub-panel for installation, especially when heater is not mounted within line-of-sight of the main electrical panel. Wiring should be sized to maintain a voltage drop of less than 3% under load. Please consult your electrician for more details.