The Best Electric Tankless Water Heater for the Modern Home

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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If you want to add a modern touch to your home or office, buying the best electric tankless water heater should be at the top of your list. Many living and working units have the conveniences of water heating systems that utilize storage tanks. However, the long-term costs of storing hot water far outweigh installing and using electric tankless water heaters.

The hot water needs of your house or office often determine the size of your tank. Nevertheless, a larger storage capacity means that you will have to give up plenty of space to accommodate your regular usage. Plus, you may not be able to avoid the risk of leakages, higher energy bills and shorter life-spans.

It can be challenging to look through the numerous options available when looking for the best electric tankless water heater. We have compiled five products to help you make the most practical purchase for your office or home.

5 Best Electric Tankless Water Heaters

1. Stiebel Eltron Tankless Heater Tempra 12 Plus Tankless Water Heater

Stiebel Eltron Tankless Heater – Tempra 12 Plus –...
  • CONTINUOUS FLOW – Advanced Flow Control patented technology...
  • SPACE & ENERGY SAVER – Its small, sleek white design saves...
  • EASY OPERATION – Electronic switch activates the hot water...
  • TEMPRA 12 PLUS – This specific model is 12kW, 240V, requires a...
  • WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric...

The Stiebel Eltron Tempra 12 Plus Tankless Water Heater ensures continuous flow thanks to the patented Advanced Flow Control. Since hot water tanks are ineffective when demand increases beyond their capacity, showers might be interrupted. However, this product guarantees comfort by keeping the supply constant with a slight decrease in case your usage exceeds the flow rate.

If you are looking to free-up space while reducing your utility bills, this electric tankless water heater is for you. The model boasts of a sleek, noise-free and compact design that does not include bulky vents. Plus, the unit combines water flow electrical control with auto-modulation to offer excellent energy efficiency.

The tankless electric water heater has a simple interface that you can use to create and store presets and monitor the temperature via a digital display. The Stiebel Eltron Tempra 12 PLus stands toe-to-toe with gas-powered water heaters because it can provide you with a flow rate of up to 5 GPM.


  • Corrosion-resistant with high durability standards because of the dual stainless steel materials.
  • The unit has Energy Star certification.Compact and noise-free design.
  • You do not have to wait for the water to warm up because the water heating system guarantees uninterrupted flow.
  • Simple to use.
  • This unit comes with a digital display.


  • A cold climate noticeably reduces the product's performance.
  • Installation expenses may be high if your pipping is far from the power supply.
  • It has a high price tag.

2. Ecosmart ECO 36 Electric Tankless Water Heater

Ecosmart ECO 36 36kw 240V Electric Tankless Water...
  • Sleek and compact design with digital output temperature display
  • ECOSMART tankless water heaters are 99.8-percent energy efficient
  • Manufactured in United States
  • Pipe Fittings:3/4 inch NPT
  • Required Breaker:4 x 40 A

Ecosmart ECO 36 Electric Tankless Water Heater offers users long-term gains of significantly slashing their heating bills. It uses self-modulation technology to regulate its energy consumption whenever you require hot water. These perks make it one of the best electric tankless water heaters in energy efficiency.

The Ecosmart ECO 36 is ideal for small apartments due to the small design that uses about 10% of the space occupied by a storage tank. The compact form still allows it to deliver a flow rate of up to 6 GPM for continuous hot water supply. Additionally, it has an activation flow of 0.3 GPM.

You can monitor the output temperature via a digital display and use the straightforward interface to tweak the settings. The Ecosmart ECO 36 water heating system will also detect temperature changes in the range of one degree Fahrenheit.


  • This unit occupies about 10% of the space used by a tank heater.
  • It has sensitive temperature sensors that notice slight variations of one degree Fahrenheit.
  • Highly durable because of the copper and stainless steel build.
  • Easy to install and use.
  • The unit has advanced self-modulating technology.
  • Reduces energy costs by heating water when it passes through the unit.
  • Continuous water flow.


  • Some clients complain of leaking.
  • Warranty guarantees are difficult to understand.

3. Rheem RTEX-13 240V Heating Chamber Residential Tankless Water Heater

Rheem 240V Heating Chamber RTEX-13 Residential Tankless...
  • External adjustable digital thermostatic control with LED display...
  • Durable Copper immersion two heating elements, field...
  • Simple installation – 1/2 NPT adapters included; side 1/2 inch...
  • 99.8% energy efficient. External controls to adjust temperature...
  • Threaded for easy replacement, simple installation, digital...

The Rheem RTEX-13 240V Residential Tankless Water Heater has the right balance of affordability and utility. The tankless model boasts an impressive energy rating that is 99.8% efficient. It achieves this standard by utilizing its external temperature control feature for incremental adjustments of one degree Fahrenheit to the hot water temperature.

Installing the product is quick and straightforward because of the tools that come with the packaging. You get a three-foot cable along with NPT adapters that ensure you are done in no time. The interface makes adjusting the temperature gauges for the hot water simple.

Rheem RTEX- 13 will provide you with a flow rate of 3.17 GPM, which is sufficient to guarantee a continuous supply of hot water to your house. It has a heating chamber with immersed copper heating elements. This build ensures high durability for years of excellent service.


  • Affordable.
  • Highly energy efficient.
  • The unit GPM ratings are comparable to natural gas-powered water heaters.
  • Sleek design to save space in your home or office.
  • This unit is ideal for residential house use where the demand for hot water is high.


  • Frigid climates negatively affect the performance of the electric water heater.
  • It might get overwhelmed when the demand far exceeds the hot water supply.

4. Bosch Tronic 3000 3.6kW US3-2R Electric Tankless Water Heater

Bosch Thermotechnology 7736505867, 3.6kW, Bosch US3-2R...
  • NEW LOW ACTIVATION FLOW RATE: A new lower activation flow rate of...
  • ELECTRIC TANKLESS WATER HEATER: 3.6 kW under-sink tankless water...
  • FLEXIBLE INSTALLATION: Can be installed in a 360 degree...
  • EFFICIENT DESIGN: Ultra compact and lightweight design with 98%...
  • IDEAL SIZE: Measures 6.6" x 12.8" x 2.9", making it the perfect...

The Bosch Tronic 3000 offers numerous advantages over previous models, such as a low activation point of 0.3 GPM. Thus, the unit is ideal for use with faucets that are designed to save water.

This product is small and works well as a supplement for an established hot water system. For instance, you can use it to supply multiple sinks in a restaurant or house. Plus, the installation process is simple and can accommodate a variety of orientations and positions to ensure it fits anywhere.


  • It does not require temperature or pressure relief.
  • The unit is compact and lightweight to fit a variety of use cases.
  • The model is made of copper materials that prolong its life-span.
  • It has a copper heat exchanger, and the heating elements have copper sheathing.
  • Low activation standard of 0.3 GPM.
  • Little maintenance required.
  • It is affordable.


  • It is not ideal for people with high hot water demands.
  • Its components have different warranty timelines.

5. Eemax EEM24013 Electric Tankless Water Heater

Eemax EEM24013 Electric Tankless Water Heater, Blue
  • Tank less water heaters provide a continuous Supply of hot water...
  • Instant, consistent and endless hot water
  • The most advanced, self-modulating technology available, meaning...
  • Compact size saves valuable storage space
  • Before purchase and installation, Please verify that this...

Saving energy is one of the most significant driving forces for people looking to change from a tank system to an electric tankless option. The Eemax EEM240013 model is an affordable unit that supplies continuous hot water whenever you need it.

You can rely on the self-modulating feature of the product to reduce your power consumption. This model only turns on when water is running through it so that you do not heat water unnecessarily.

The unit uses stainless steel materials to ensure that it can keep serving users for years to come. Additionally, it is small in size to save you valuable storage space.


  • Instantaneous and constant supply of hot water.
  • Self-modulating.
  • Small to save space.
  • Reliable customer support.


  • Expensive.
  • You need to have a 60AMP breaker to use the unit.

What to Consider When Selecting the Best Electric Tankless Water Heater

1. Installation costs

It is best to install electric tankless water heaters at the source of water or along the pipping in your home or office. Since these products lack any storage capabilities, the heating power supply must be close to pipes. You need to check if your house requires significant modifications to accommodate a tankless heater.

Installation costs of tankless heaters may also increase if you live in an older house with a limited power source. It is best to check the energy consumption of any unit to avoid needing to upgrade your power supply.

2. The water temperature of your supply

Electric water heater models should reliably increase the water temperature of your supply to the level you desire. If you have cold water coming into your house, the flow rate of the hot water system will change. Hence, it is beneficial to calculate the temperature rise that you want to make the most practical choice of water heaters.

Ensure that the climate in your area is conducive to the water heater you want to buy. Otherwise, you will have to deal with colder showers during specific times of the year.

3. Determine flow rates

Flow rates, indicated by GPM, are essential considerations when creating reliable heating systems. You can calculate the amount you need by figuring out the flow rate of all the faucets, home appliances and showers that require hot water during peak demand times.

Add all the GPM for the output, then compare it to the capacity of the product you want to buy. Ideally, tankless water heaters should supply more than you need to ensure that you get a steady stream.

4. Warranty

Each manufacturer of tankless water heaters offers their clients varied warranties that may differ from one model to another. For instance, some companies want you to get a professional to install your unit for their warranty to apply.

It would be best to make a comparison of the various warranties on offer before deciding on a model. After all, a company's commitment to customer satisfaction highlights their confidence in the models they manufacture.

5. Energy savings and efficiency

Electric tankless water heaters promise significant savings when compared to using a hot water storage tank. Heating water when it is required helps to reduce the energy used to keep it hot in a separate tank.

Look out for high Energy Factor ratings, as these indicate how much water the model can heat with one unit of power. Admittedly, a gas-powered water heater is more cost-effective because the fuel is currently cheaper than electricity.

Frequently Asked Questions (FAQs) on Electric Tankless Water Heaters

1. What is the best electric tankless water heater to buy?

The Stiebel Eltron Tempra 12 Plus Tankless Water Heater is the best overall in energy efficiency, durability and reliability. Its advanced flow control allows you to enjoy hot water on-demand without interruptions. Plus, the model lasts for a long time due to the double stainless steel construction.

Additionally, you will not be able to tell when the unit is running because it is noise-free. The small size makes it suitable for people looking to free up some space in their basement while meeting their heating needs.

2. Are electric tankless water heaters worth it?

Although the costs of installing tankless models of electric water heaters are pretty high, the savings you get from long-term use make it worthwhile. A unit will be cheaper to maintain than a hot water tank because the chances of leakages are pretty low.

The maintenance cost of an electric tankless water heater is much lower than the gas-powered counterparts. In case you are using the latter, you may need to meet up with plumbing experts annually to check on your unit. On the other hand, you may need to replace some parts of your electrical model after a couple of years.

3. What size electric tankless water heater do I need for my house?

The flow rate of your peak consumption and the temperature rise you require should help you decide on the size you need. People in cold areas require hot water systems to achieve the necessary temperature increase while keeping up with their heating demands. Similarly, a house with significant hot water needs should go for a unit with a high GPM.

Most manufacturers offer customer support that will help you in choosing the correct size. You can go over the various usage statistics for your home to figure out which model will cater to all your needs. Taking the time to understand the various aspects of electric tankless water heaters will save you time and money in the long run.

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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