Review of Stiebel Eltron Tempra 20 Plus

German-backed technology provides huge savings in the long run

Stiebel Eltron Tempra 20 Plus Electric Tankless Whole House Water Heater, 240 V, 19.2 kW
Rating: (4.8 out of 5 stars)

Type of HeaterElectric Tankless
Size / Capacity3.7 GPM
Dimensions16 5/8 x 14 ½ x 4 5/8 inches

Stiebel Eltron Tempra 20 Plus

The electric Stiebel Eltron Tempra 20 Plus is the less expensive alternative to gas-powered tankless water heaters, both in terms of unit cost and installation fees. This 240 V whole house water heater pulls 19.2 kW when in use. Because the unit is backed by efficient German technology, the hot water portion of your electrical bill is reduced by 15-20%. And because venting is not necessary, the unit is almost 100% efficient.

Review Details

This model can heat a maximum of two bathtubs in warmer regions where the incoming water temperature averages 70oF; and only one bathtub in cooler regions where the incoming water temperature averages 40oF.

Like other Stiebel Eltron models, the Tempra 20 Plus is often used in vacation homes, and it activates at a low 0.58 GPM to reach a maximum rate of 4.5 GPM. Maximum operating pressure is 150 PSI.

Priced at under $600 online (depending on the retailer), it features a digital display for temperature readings and a dial for setting preferred output temperature. The cover is hinged to allow quick and easy opening of the unit should problems arise. The unit is guaranteed for three years.

The good

Delighted owners of the Stiebel Eltron Tempra 20 Plus are pleased about the unit’s:

  • Consistent temperature
    Due to the Tempra Plus-exclusive Advanced Flow Control, the unit is capable of maintaining an even and constant temperature regardless of demand. This feature regulates water flow automatically to prevent unwanted fluctuations in temperature. It is ideal for applications that require high temperature and with unpredictable flow rates.
  • Durability
    One owner said that the unit showed no signs of problems even after 3½ years of constant use.
  • Small size
    Measuring just 16 5/8″ x 14 1/2″ x 4 5/8″, it is ideal for those with limited space. And if you’re replacing a tank unit with this one, you reclaim storage space.
  • Clear instructions
    Owners have cited that Stiebel has “the best and very clear instructions” among water heater manufacturers, and for this particular series the company has provided a guide on choosing the appropriate size. Please see

The not so good

Owners of the Stiebel Eltron Tempra 20 Plus point out the following:

  • Installation costs
    Like other tankless systems, this unit requires professional installation which will increase your expenses. It requires a minimum of two 50 Amps circuit breaker and two #8 gauge copper wires. But if you are replacing a gas tankless unit with this model, installation will be cheaper because venting is not required.
  • Pressure lowers when several fixtures are used at the same time
    According to owners, water flow is noticeably reduced when two or more fixtures are run simultaneously but you still get hot water.

Our Verdict

If you previously owned a tankless system, the switch to this electric tankless water heater will not be too much of a burden. However, if this is a first time purchase, pay particular attention to the electrical requirements and double check if your current service can handle 125 Amp; better consult an electrician.For those living in Quebec, Canada, one owner pointed out the required wiring does not match the local code. Again, the electrician is the best person to recommend how to adapt this model to your home.

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