Stiebel Eltron Tempra Electric and Tankless Water Heater: Buying Tips

Stiebel Eltron TempraStiebel Eltron Tempra

High efficient and performing Stiebel Eltron Tempra is an electric tankless water heater designed to replace the conventional tank-type heater and supply plenty of hot water to a single, point-of-use application also multiple fixtures in the whole-house residential and commercial water heating.

Stiebel Eltron Tempra: Advantages and models review

Reduced energy usage

The Tempra is known for its advanced and reliable technology, excellent performance, and design that minimizes energy consumption up to 20% when compared to the standard tank type. Due to the on-demand heating, standby heat loss is eliminated, and the energy efficiency is close to 100%.

Small and compact design

Utilizing the tankless design, Stiebel Eltron Tempra is able to provide an endless hot water supply and occupy much less space than the conventional type. As opposed to the tank-type units, which are installed on the floor, Tempra, with the small and lightweight design, is mounted either on the wall, inside the cabinet, or under the sink, freeing up the floor space for other use.

Stiebel Eltron Tempra has a compact and sleek design, and a sturdy coated steel encase, which allows installation for both residential and commercial use, almost anywhere inside your home, condo, apartment, or cottage, office, and without occupying the valuable space. It can also be installed outdoors but protected from the rain and cold weather elements.

Precise temperature control

One of the leading advanced features Tempra has to offer is the thermostatic temperature control which allows you an accurate, constant, and reliable temperature control, resulting in all-day comfort. It is built to work with the cold incoming water but can also be used with a solar heating system and preheated water of up to 131 F.

Advanced technology

Stiebel Eltron's microprocessor technology allows accurate temperature control, thanks to the frequent readings of the flow and temperature sensors. You can set the temperature of hot water between 86 F and 140 F while the unit modulates the power to keep the temperature steady, prevent temperature fluctuation and discomfort even if the water flow changes.

Based on the set temperature, the heating elements are engaged in stages providing heating power from its minimum to maximum with the smooth transition. That is what allows great performance, savings, and customer satisfaction.


Installation of the electric tankless water heater such as those coming from Tempra is easier than its gas counterpart, but due to the high Amp draws, it might be required to upgrade the electrical panel. All the models, from the smallest Tempra 12 to the largest Tempra 36, require 240 V and must be hardwired.

This is why it is recommended to contact the professional installer for this job.

Stiebel Eltron Tempra: Model review

There are two series of Tempra that Stiebel Eltron designs:

  • Tempra series
  • Tempra Plus series

The difference between these two groups is not only in the number of available models but also in the included features. The Tempra series comes with several models ranging from 9 to 24 kW, while the Plus series also includes stronger models with 28 and 36 kW power.

Smaller models are known as point-of-use water heaters and should be selected based on the incoming water temperature, desired temperature, and flow rate.

Larger or whole-house models are more expensive but also more advanced and are selected based on the temperature of the incoming water, the maximum desired temperature of hot water and the number of fixtures used.

Stiebel Eltron Tempra series

Stiebel Eltron TempraStiebel Eltron Tempra

Stiebel Eltron, Tempra 12, and 12 Plus are able to provide the power from its minimum of 9 kW when working on 208 V to the maximum of 12 kW when operating on 240 V. Tempra 12/Plus uses one heating module that provides up to 3 GPM with the max. temperature rise of 27 F.

It is mainly used as the point-of-use (POU) water heater in warmer areas of the US; low flow applications, like one kitchen sink or bath at the time and one-bath homes. As opposed to all other Stiebel Eltron models where the minimum water flow activation rate is 0.5 GPM, Tempra 12 / Plus requires less - 0.37 GPM. With a weight of 13.5 lbs, this is the lightest unit.

Tempra 15 and 15 Plus have a minimum power of 10.8 kW when working on 208 V and a maximum power of 14.4 kW when on 240 V. Tempra 15/Plus uses two heating modules that provide water flow of 3 GPM but with the higher temperature rise of 33 F. 

In colder regions, these models operate as POU in low flow applications, while in warmer areas such as Florida and the Caribbean, these can be used in whole-house applications such as one-bath homes.

Tempra 20 and 20 Plus have a minimum power of 14.4 kW when working on 208 V and max. power of 19.2 kW on 240 V. The models utilize two heating elements that can provide water flow of 3 GPM at the higher 44 F temperature rise or the maximum of 4.5 GPM at 29 F temperature rise. Stiebel Eltron Tempra 20 / Plus heaters are designed for homes situated in the warmer areas (e.g., southern parts of the US), as the whole-house water heater, or for homes with a moderate water demand (1-2 bath homes).

Stiebel Eltron Tempra 24 has the min. power of 18 kW when working on 208 V, and max. power of 24 kW on 240 V. Tempra 24 uses two heating modules that can provide a water flow of 3 GPM at the temperature rise of 54 F or a maximum of 4.5 GPM at 37 F rise. Tempra 24 / Plus are the most popular models and sizes of all Stiebel Eltron tankless water heaters and are used mainly in whole-house applications where a higher flow rate is needed but in warmer areas. Tempra 24 / Plus are recommended for standard residential homes with 2-3 baths.

Tempra Plus series

Stiebel Eltron Tempra PlusStiebel Eltron Tempra Plus

Stiebel Eltron Tempra Plus models are more advanced than the above standard models. The Plus models are equipped with the microprocessor and the Advanced Flow Control technology that adjusts the flow rate of the water when you exceed the capacity of the system. The result is precise temperature control at a consistent level. 

When comparing models with other manufacturers, it can be seen that in low and medium demanding applications, the desired temperature can be met, but in high-demanding applications, Stiebel Eltron models have the advantage. This advantage is called an Advanced Flow Control, and it automatically reduces (adjusts) the water flow to meet the set temperature – which is not found on other brands.

This is especially important if you live in a colder area and cannot install a larger model.

The Tempra Plus series, except the models explained above, comes with two more; 29 Plus and 36 Plus. These are the heaviest, most powerful, and can provide more hot water but require a regular operation.

Tempra Plus 29 is providing a min. power of 21.6 kW on 208 V, and max. power of 28.8 kW on 240 V. It has three heating modules, and its maximum temperature rise at 3 GPM is 66 F, while for the maximum flow of 4.5 GPM, the rise is 44 GPM. It is recommended for homes situated in the colder areas or for homes with a high water demand (e.g., 3-bath homes).

Tempra Plus 36 is the largest model from Stiebel Eltron, providing min. power of 27 kW on 208 V, and max. power of 36 kW on 240 V. It has three heating modules, and its maximum temperature rise at 3 pm is 82 F, while for the maximum flow of 4.5 GPM, the temperature rise is 55 GPM. It is designed for homes situated in the colder areas with high water demand (e.g., 4-bath homes).

All Tempra tankless water heaters have the same size, same 99% efficiency, same 3/4" NPT pipe fitting, but come with different water flow, many heating modules, and power outputs.

Customer reviews


  • It doesn't take up considerable space. 
  • It was easy to install and easy to use.
  • A dial on the front of the unit allows you to adjust the temperature in seconds and precisely.
  • Provides saving on the electric bills.
  • Parts are made of corrosion-resistant material.


  • Short three-year warranty.
  • 36 kW model requires a 3X60 amp breaker, which is a lot of panel space. You have to upgrade the electrical panel to support the Tempra 36.
  • Installing a Tempra 24, for example, requires an expensive 2x6 wire.
  • Some complaints were related to the insufficient hot water for two showers and low performance (warm instead of hot water).
  • Tempra 24 doesn't work so well if the incoming water is cold. It is better for warmer climates.


Stiebel Eltron Tempra tankless water heaters are top-of-the-line electric water heaters known for their high quality and reliable performance. Due to the tankless design, they are 99% efficient, and as long as there is a water supply, they will supply hot water continuously and in an endless supply. Tempra models are one of the most popular small electric water heaters and top sellers on amazon.com.

As it can be seen from the above reviews, the Plus version is a more advanced group. If you want to buy an electric water heater for a small house, apartment or cottage, or a large house but for the distant sink, look for the point-of-use models (POU). They have lower water flow and power, and the requirements for the electrical work are not demanding. The recommended models are Tempra 12 and Tempra 15.

If planning to buy a Tempra for a larger house and use hot water not one, but two or more fixtures, look for the whole-house models, such as the popular Tempra 24, Tempra 28, even Tempra 36 if demanding for hot water is high. Be advised that it might be required to upgrade the electrical panel. Contact the electrician for the estimate and work.

emergency plumber

You might like these