We can agree, finding the best whole house electric tankless water heater is never a fun task.
But having the right model in your home will let your family enjoy unlimited hot water in no wait. Best of all, tankless water heaters are way more energy-efficient than tanked models.
Here are the best whole house electric tankless water heaters you can buy in 2025:
- Easy To Install: Stiebel Eltron 239219
- Consistent Hot Water Flow: EcoSmart ECO 27
- Budget Option: Thermomate ET180
- Fast Heating: Rheem RTEX-24
- Sturdy: BLACK+DECKER BD-27-DWH
- Energy-Efficient: Stiebel Eltron Tempra 15 Plus
| 6 Best Whole House Electric Tankless Water Heaters | ||
|---|---|---|
Easy To Install | Stiebel Eltron 239219 | |
Consistent Hot Water Flow | EcoSmart ECO 27 | |
Budget Option | Thermomate ET180 | |
Fast Heating | Rheem RTEX-24 | |
Sturdy | BLACK+DECKER BD-27-DWH | |
Energy-Efficient | Stiebel Eltron Tempra 15 Plus | |
Easy To Install: Stiebel Eltron 239219
- Easy to install – clear instructions & simple installation process
- Automatically remain water temperature - the exclusive Advanced Flow Control patented technology
- Elegant looking - all-white design
- The back-lit drowns out the led screen when modifying the temp control
- Not work well during busy times
Hiring a licensed plumber and electrician to install a whole house electric tankless water heater is costly. If you want to save the cost by installing it yourself, consider the Stiebel Eltron 239219.
The installation goes easy in less than an hour, with very basic hand tools needed and no venting required. The directions are simple and straightforward.
Stiebel Eltron's water heater operates quietly and remains the water temperature pretty well, thanks to the exclusive Advanced Flow Control patented technology.
Unlike other counterparts, the Stiebel Eltron 239219's elegant all-white housing adds a great modern touch to the space and flexibly matches any bathroom decor.
| Stiebel Eltron 239219 Specifications | |
|---|---|
Dimensions | 4.63 x 16.63 x 14.5 inches |
Maximum Operating Pressure | 300 PSI / 20 BAR |
Temperature Range | 68° to 140°F |
Maximum Power Output | 12kW, 240V |
Highlight Features | clear instructions & simple installation process the exclusive Advanced Flow Control patented technology all-white design |
The Stiebel Eltron 239219 is easy to install, high-quality, and beautiful at a good price.
Consistent Hot Water Flow: EcoSmart ECO 27
- Provide consistent hot water flow – 27kW power
- Very space-saving - the 3.75
- Expensive
The EcoSmart ECO 27 is a powerful 27kW whole house electric tankless water heater that produces 2.7 to 6.5 gallons of hot water per minute. So strong that even when the incoming water temperature drops as low as 37 degrees F, its waterflow is still nearly 3 GPM.
So, it's not exaggerating to say the ECO 27 never runs out of hot water and actually works for big families, or Jacuzzi or large Roman-style tubs.
Performance aside, the 3.75" ultra-slim profile of the ECO 27 is incredibly space-saving. It's 90% smaller than tanked water heaters, saving up to 12 cubic feet of space.
The ECO 27 is ETL Listed and UL-499 certified, which ensures safety.
| EcoSmart ECO 27 Specifications | |
|---|---|
Dimensions | 17 x 17 x 3.5 in. |
Maximum Operating Pressure | 150 PSI |
Temperature Range | 80°F - 140°F |
Maximum Power Output | 27 KW at 240 Volts |
Highlight Features | 27kW power the 3.75" ultra-slim profile |
You’ll never be out of hot water while taking a shower or washing dishes with the EcoSmart ECO 27. It’s the best option for consistent hot water flow.
Budget Option: Thermomate ET180
- The most affordable
- Prevent mineral buildup, corrosion, and lime scale – separated water tube and heating element
- Energy-saving - self-modulating energy consumption technology
- The temperature control is not as precise as our other picks
- Not aesthetic
You don't need to invest a lot to get hot water. Our budget option - the Thermomate ET180 - costs well nearly half what our other picks do and is durable.
It's safe, easy to install, and leak-resistant. Its water tube and heating element are separated to prevent mineral buildup, corrosion, and lime scale in the long-term use, which minimizes the maintenance.
Better yet, its self-modulating energy consumption technology helps save up to 60% on water heating cost than standard tank water heaters.
Expect to sacrifice a bit of precision in the temperature control for that affordable price, though.
| Thermomate ET180 Specifications | |
|---|---|
Dimensions | 17.12 x 13.12 x 3.12 inches |
Maximum Operating Pressure | 150 PSI |
Temperature Range | 80°F to 140°F |
Maximum Power Output | 76 amps, 240V/18kW |
Highlight Features | separated water tube and heating element self-modulating energy consumption technology |
Looking for the best budget option? Try the Thermomate ET180.
Fast Heating: Rheem RTEX-24
- Heating in seconds
- Easy to use - bright LED temperature display & large knob
- Installation is very time-consuming
The Rheem RTEX-24 is the only whole house electric tankless water heater we tested that heats up and delivers hot water in seconds, typically from 3-5 seconds depending on the incoming water temperature and the selected temperature setting.
At 24kW power, it reaches the max flow rate of 5.9 GPM with no difficulty, which is perfect for big families with high hot water demand.
The bright LED temperature display and large knob are great add-ons.
All-in-all, this is a great deal for the price.
| Rheem RTEX-24 Specifications | |
|---|---|
Dimensions | 18.25 x 14.5 x 3.5 inches |
Maximum Operating Pressure | 150 PSI |
Temperature Range | 80-120 degrees F |
Maximum Power Output | 24kW |
Highlight Features | Fast-heating bright LED temperature display large knob |
The Fast-Heating Rheem RTEX-24 is one of our favorites this year.
Sturdy: BLACK+DECKER BD-27-DWH
- Sturdy – corrosion-free stainless steel internal assembly
- Ideal for 6 applications simultaneously - 27kW power
- A bit bigger than other picks
The BLACK+DECKER BD-27-DWH is assembled of stainless steel internal piping and canisters, and this offers some advantages, because it prevents corrosion and holds up well with time.
This electric tankless water heater is slightly bigger than our other picks at 21.4" W x 15.9" H x 7.5" D, but it's still space-saving compared to traditional models.
It operates at 27kW power, which is powerful enough for 6 applications or 3 bedrooms at the same time.
| BLACK+DECKER BD-27-DWH Specifications | |
|---|---|
Dimensions | 21.4 x 15.9 x 7.5 inches |
Maximum Power Output | 27kW |
Highlight Features | corrosion-free stainless steel internal assembly 27kW power |
In need of a sturdy and powerful whole house electric tankless water heater? consider the BLACK+DECKER BD-27-DWH
Energy-Efficient: Stiebel Eltron Tempra 15 Plus
- Energy-efficient – the smart self-modulating technology
- Ensure to provide the desired hot water on the demand – the Advanced Flow Control function
- Durable - seismic-proof construction
- Expensive
- The instructions could be clearer
The Stiebel Eltron Tempra 15 Plus scored high marks on energy efficiency, thanks to its smart self-modulating technology that minimizes the energy consumption to heat the water.
This whole house electric tankless water heater is proven to save at least 15% on your monthly electric bill.
Its Advanced Flow Control function ensures to provide water at the selected temperature setting even when the demand exceeds capacity.
While the Stiebel Eltron Tempra 15 Plus is not a budget-friendly option, it's extremely durable thanks to the seismic-proof construction to hold up surprisingly well in long-term use.
| Stiebel Eltron Tempra 15 Plus Specifications | |
|---|---|
Dimensions | 19.5 x 21.5 x 8.5 inches |
Maximum Operating Pressure | 300 PSI |
Temperature Range | 86°F - 140°F |
Maximum Power Output | 240 V, 14.4 kW |
Highlight Features | the smart self-modulating technology the Advanced Flow Control function seismic-proof construction |
Fear no more about the rising electric bills while using hot water, the Energy-Efficient Stiebel Eltron Tempra 15 Plus will help you minimize the energy consumption for hot water.
How To Choose The Best Whole House Electric Tankless Water Heater?
Flow Rate
GPM, referring to gallons per minute, is the measuring unit of water or any other sort of liquid. It lets you know how much water goes through a device, also called flow rate.
Certain equipment, such as showers and washing machines, demand extra water.
Knowing how much water and at what temperature certain appliances utilize hot water is a crucial component in selecting the correct size of a tankless water heater.
Below is a useful guide for flow rates and average temperature.
Use case | Average temperature (in degrees F) | Flow rates (in GPM) |
Kitchen sink | 110 | 1.5 |
Dishwasher | 110 | 1.5 |
Washing machine | 120 | 2 |
Shower | 104 | 2.5-3 |
Bathtub | 102 | 4 |
Temperature Rise
This term lets you know how well a tankless water heater heats water to the set temperature.
To figure out the right temperature rise capabilities of a whole house electric tankless water heater, you need to determine the average temperature of water coming to your house.
For example, the hot water temperature for showering is from 104 to 105 degrees; if the incoming water is 34 degrees F, then you’ll want a water heater with a temperature rise capability of around 70-71 degrees F.
An online heat map tool is helpful to figure out your average water temperature.
You’ll need a whole house electric tankless water heater with a high temperature rise factor in cold climates and vice versa.
Maximum Power Output
The maximum power output of electric water heaters is measured in kilowatts (kW).
To find out the kW of heating capacity that a whole house electric tankless water heater requires to offer, you need to determine:
- Local climate
- Temperature rise
- Maximum normal flow rate
- How many people are in your home
If you’re a beginner, it’s helpful to ask your installer or retailer.
Which Brands Make The Best Whole House Electric Tankless Water Heater?
Stiebel Eltron
Started in 1924, Stiebel Eltron is one of the most dependable Germany-based manufacturers of central heating products. They’re renowned for offering efficient solutions for hot water, air conditioning, room heating, and more.
Best of all, they have been chosen a 'Superbrand' for the 5th time in a row.
EcoSmart
EcoSmart is owned by Eemax, a leading manufacturer of electric tankless water heating solutions for industrial, commercial, and residential applications in the United States. Their water heaters stand out from other counterparts for ultra-long lifespan and top-notch quality.
Thermomate
Thermomate provides numerous product lines of appliances, consisting of water heaters, range hood, cooktops, and more. Their water heaters are varied in power source options, sizes, and features.
Rheem
Rheem is one of the best mid-level water heater brands and has been in the industry for a century. They’re known for offering durable, high-quality water heaters at affordable prices to suit most homes.
FAQs
Is it worth the money to get an electric tankless water heater?
Yes, it is. For many consumers, the long-term benefits of electric tankless water heaters outweigh the upfront cost.
Depending on the size and type of the water heater, a tankless model is up to 34% more efficient than usual, which results in yearly savings of more than $100.
Can an electric tankless water heater run a whole house?
Yes, it can. There are many electric tankless water heaters specifically built to run a whole house and help the homeowners optimize energy costs.
As a great plus, tankless water heaters offer more steady flow of hot water than the tanked model. This means you’ll never run out of hot water.
Do electric tankless water heaters use more electricity?
No, they don’t.
Electric tankless water heaters are renowned for consuming less electricity than regular models.
An electric tankless water heater can be 8-34% more efficient than a traditional water heater, depending on the amount of hot water the household consumes daily.
What size tankless water heater do I need for a family of 4?
For a family of 4, it’s recommended to choose a 20-28kW electric tankless water or a gas tankless water heater at 8-10 GPM.
Do electric tankless water heaters work in cold climates?
Yes, they do. Electric tankless water heaters are built to work well in both cold and warm weather climates.
Conclusion
It’s challenging to choose the best whole house electric tankless water heater for your needs and budget, right?
Our comparative and intensive review has something for everyone, from budget-conscious shoppers to beginners. We also have options that heat up in no wait, offer consistent hot water flow, or save your money on monthly energy bills.
Take your time and carefully consider all the recommendations. Happy shopping!
