Tankless Electric Water Heater FAQs

Yes, we do. For a complete collection of all our available videos, please view our YouTube channel.

Tempra^®, DHC, and DHC-E models must be plumbed vertically with water fittings facing downward only. Mini^™ models can be plumbed with pipes facing either up or down, but never sideways.

On all models, you must remove the cover to access the thermal safety reset. MAKE SURE YOU DISCONNECT THE POWER BEFORE OPENING THE CASE. On Tempra^® and DHC-E models, the safety thermal reset buttons are small red or gray buttons located on top of each copper heating vessel. On DHC models, the reset buttons are along the top right side of the heating vessel. On Mini^™ models, the safety thermal reset button is a round, flat, black button located between the wiring block and water connection pipe.

Below is a video showing how to reset the safety thermal cutout on a Tempra^® unit.

Yes, however don’t forget it is an electrical unit that must be protected from the elements. Install it so that it is protected from rain, temperatures below freezing, and critters. Fried lizards are not good!

No, these tankless electric units do not require any venting.

Stiebel Eltron tankless electric water heaters are designed for a very long service life, but actual life expectancy will be directly affected by water quality and use. If you do not already know the quality of your water, we advise testing (your water department may be able to assist). Installing a non-salt based softener or inline filter may prolong the life of your unit. Stiebel Eltron recommends the Scale TAC-ler (our Part No. 692442) for this purpose. To ensure consistent water flow, we recommend periodically checking for and removing any scale and dirt in the faucet aerators and showerheads, and in the filter screen in the unit. Depending on water hardness, scale build-up may need to be flushed from the unit every six months to a year. This will prolong the life of your water heater, and help ensure optimal performance. We recommend our Flow-aide Descaling Kit (our Part No. 540000) for this purpose. Alternatively white vinegar or CLR^® Calcium, Lime & Rust Remover may be used. More info on water quality ›

Descaling procedure, step-by-step:
1. Disconnect power to water heater.
2. Close hot and cold isolation and service valves and remove service caps.
3. Pour 1.5 gallons of water into bucket and place under water heater.
4. Add contents of 1 quart bottle of Flow-Aide into bucket (bucket should be filled approximately ½ full).
5. Connect one hose pump, and other end of same hose to cold service valve. Place pump in bucket.
6. Connect second hose to hot service valve. Place other end in bucket.
7. Open both hot and cold service valves.
8. Plug pump into grounded receptacle.
9. Allow pump to circulate Flow-Aide solution through heater for 30-45 minutes. Unplug pump.
10. Close cold service valve. Remove hose from cold service valve, and replace service cap.
11. Disconnect the hose from the pump and remove pump from bucket. Discard Flow-Aide solution.
12. Flush tankless water heater for 3-5 minutes or until water flows clear by opening the cold isolation valve and allowing water to exit through the hot service valve into a drain or bucket. If using a bucket, empty periodically.
13. Close hot service valve. Remove hose from service valve and replace service cap.
14. Open hot isolation valve.
15. Connect power to water heater and return appliance to service.

Our smaller, point-of-use water heaters are sized according to the desired hot water temperature, the temperature of the incoming ground water, and the flow rate at the fixture. Our larger, more sophisticated water heaters are sized according to the maximum hot water temperature desired, the temperature of the incoming ground water, and the number of bathrooms or appliances that will be supplied. Please refer to each model’s sizing guide.

We recommend that homeowners hire a licensed plumber and electrician to install Stiebel Eltron tankless water heaters.

Stiebel Eltron tankless water heaters must be hard wired.

Subject to flow rate, Tempra^® and DHC-E models can reach temperatures of up to 140°F. DHC models can reach temperatures of 130°F.

Mini models require 3/8” O.D. braided steel or flex connectors. DHC and DHC-E models require ½” NPT braided steel or flex connectors. Tempra^® models require ¾” NPT braided steel or flex connectors.

First turn off your power source at the breaker box. Next turn off the water line using the incoming water shut-off valve. Then disconnect the plumbing (be careful of water spills). Our units do not self-drain so the unit must be taken off the wall, and tilted to completely remove the remaining residual water. Another option for winterization is to circulate nontoxic antifreeze into the unit, and leave it in the unit until it is ready to be used again. Also, because of their compact size and easy installation, units may always be removed and stored in a non-freezing area elsewhere.

You can never run out of hot water and there are no standby losses! Save money on electrical bills each month. Our tankless electric units are 99% efficient. A Stiebel Eltron tankless electric water heater only runs when hot water is needed. Tank-type units must keep water hot, even when you are not home. Save space: our largest whole house tankless unit is about the size of a briefcase. Stiebel Eltron invented tankless water heaters about 90 years ago. Our water heaters have been designed and are continually tested to ensure they are the best tankless water heaters, and that they will last.

Yes, Stiebel Eltron tankless electric water heaters are ideal for both commercial and residential applications.

Yes, our Tempra^® and DHC-E series have temperature sensors and can accept preheated incoming water temperatures of up to 131 °F.

First, look at your installation manual and check the troubleshooting guide there. All Stiebel Eltron tankless electric water heater installation manuals are on our website. We also have knowledgeable technical support staff who can assist with consultation and troubleshooting. Email us or call 800.582.8423 for help with your problem.