How much does it cost to install a Tempra Tankless Water Heater?

Tankless Installation Cost

The installation cost of a tankless water heater is one of the most common questions we get at E-Tankless Water Heaters. It is also one of the most challenging to answer as it can vary considerably depending on your unique situation. A variety of factors can influence the cost of installing an electric tankless water heater in your home, including if you have sufficient electrical service, which model you choose, the distance between your breaker box and the installation location, whether you hire contractors or do the installation yourself, and if you are working in a finished space.

Professional Installation or DIY

We recommend hiring an electrician and / or plumber for the installation of any tankless water heater. That being said, the installation of a Stiebel Eltron Tempra or Tempra Plus series tankless water heater is quite simple for a professional. If you choose to do the installation yourself, you can reduce the installation cost, but please make sure to follow all local plumbing and electrical codes. A full installation guide is available on our website. Installing the unit yourself does not affect the manufacturers warranty.

Model of tankless being installed

Breaker size, number of breakers, and amount of wire required all depend on which model of tankless water heater is best suited for your application. On the lower end of the spectrum, the Tempra 12 and Tempra 12 Plus require a single 50 amp double pole breaker and a single run of #6 gauge wire. The most powerful units we carry, the Tempra 36 and Tempra 36 Plus require three of those 50 amp double pole breakers and three runs of #6 gauge wire. Our most popular Tempra 29 and Tempra 29 Plus require three 40 amp breakers and three runs of #8 gauge wire. Larger breakers and thicker wiring cost more than their smaller and higher gauge counterparts.

Distance between tankless & electrical panel

A shorter distance between your tankless installation and your electrical panel will reduce your installation costs. The longer the run of wiring required, the more expensive the installation in both labour and materials costs. If you are installing the tankless in new construction it will be a balance between minimizing this distance, and minimizing the distance between the tankless water heater and the most commonly used hot water fixtures. If you are installing in a pre-existing home and replacing a traditional tank, it is often most economical to install your tankless water heater where your traditional tank was located. This will minimize the plumbing changes.

Electrical Service

Heating water as it flows through a tankless requires higher amperage than slowly heating it in a tank. Depending on which model best suited for your application, you may need anywhere from a 100 - 300 amp electrical service to your home in order to operate it. If your home doesn't have sufficient electrical service and you'd still like to install an electric tankless water heater you will need to upgrade your electrical service. This usually involves running new wiring onto the property and upgrading your electrical panel so can add considerably to the cost of installation. We always recommend checking your electrical service before puchasing any electric tankless water heater. If you have insufficent amperage to the home we recommend getting a quote on the cost of upgrading your service before purchasing an electric tankless.

The following chart shows the recommended electrical service for each Tempra / Tempra Plus model we carry.

Model Recommended
Maximum Amperage
@ 240 V
Maximum Amperage
@ 208 V
Recommended Household
Electrical Service
Recommended Minimum
Wire Gauge
Tempra 36 / 36 Plus 3 x 50 AMPS * 150 AMPS 132 AMPS 300 AMPS 3 x #8 AWG*
Tempra 29 / 29 Plus 3 x 40 AMPS * 120 AMPS 105 AMPS 200 AMPS 3 x #8 AWG*
Tempra 24 / 24 Plus 2 x 50 AMPS * 100 AMPS 88 AMPS 150 AMPS 2 x #8 AWG*
Tempra 20 / 20 Plus 2 x 40 AMPS * 80 AMPS 70 AMPS 150 AMPS 2 x #8 AWG*
Tempra 15 / 15 Plus 2 x 30 AMPS * 60 AMPS 52 AMPS 100 AMPS 2 x #10 AWG*
Tempra 12 / 12 Plus 1 x 50 AMPS * 50 AMPS 44 AMPS 100 AMPS 1 x #8 AWG*

* 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. The above specifications are only guidelines. If your home is already equipped with a large number of electrical appliances, you may require a larger electrical service than the one recommended above. Please consult an electrician before placing an order.

New construction vs pre-existing

New construction installations are almost always cheaper than replacing a traditional tank style water heater in a pre-existing home, especially if the installation location is finished and wiring must be snaked through existing walls. It is also usually much cheaper to install a larger electrical service to the home during initial construction than it is to upgrade your electrical service at a later date.