Who likes bathing in cold water in winter? Weirdos, right. The electric tankless water heaters are ready to serve hot water every time you turn on the faucet or shower early in the morning.
The electric tankless water heater has so many benefits, and because of that reason, the demand for tankless heaters is growing among consumers rapidly.
We have listed the top electric tankless water heater and their benefits. We have also developed the buying guide for your ease.
Stiebel Eltron Tempra 24 Plus (Best Overall)
Sio Green SIO18 (Most Hign-end & Lasts Longer)
Ecosmart 36 (Highest Hot Water Flow Rate)
Rheem RTEX-13 (Cheapest yet Quality Heater)
EcoSmart ECO 11
Best Electric Tankless Water Heater
Founded in 2008 as SuperGreen and later changed to SioGreen, they are known for making corrosion-free water heaters. SioGreen sells water heaters in Canada, Asia, and North America through authorized retailers.
SIO 18 provides water with a flow rate of 4.4 GPM, so you can use 3 shower heads simultaneously. In a cold region, the heater will allow you to run 2 shower heads together, and in an extremely cold region, it will supply enough hot water for 1 shower and 1 sink.
Unlike other electric tankless water heaters, the SioGreen SIO18 uses quartz infrared heating elements that increase the performance and efficiency of the heater. The quartz prevents limescale and calcium buildup into the system. The infrared quartz material is recyclable.
The product has a temperature control range of 60°F to 140°F and can be changed in the interval of 1°F on an easy-to-read LED screen. The product is a little heavier than its peer as it weighs 27 pounds.
The automatic modulation technology calculates the difference between the desired temperature and current temperature and only uses the required power, thus offers you 98% power efficiency. It requires two 240V 40Amps breakers and 8 AWG wires.
The installation of the product is easy, but it is advisable to call an expert. The tankless water heater requires nearly no maintenance, and it is suitable for home use as well as commercial.
The heater is CE certified as well. It comes with a 10 years warranty and 30 days money-back guarantee.
What we like
- It has a power efficiency of 98%.
- Infrared quartz material prevents limescale and calcium buildup.
- It has a temperature range from 60°F to 140°F.
- It comes with a 10 years warranty.
What we don’t like
- It is heavy as it weighs about 27 pounds.
Stiebel Eltron is a German manufacturer of high-quality water heaters and an inventor of patented Advanced Flow Control. Steibel Eltron Tempra 24 Plus is one great product suitable for 2 baths.
The sleek-looking design model only weighs 15 pounds, and it is capable of running 3 showers simultaneously at the rate of 5 GPM in an area with groundwater of more than 72°F. So, if you have a big family and live in a cold climate area, then this is the best electric tankless water heater for a house, in my opinion. You also need to purchase the water softener separately if your house has hard water.
In a region that has a temperature ranging from 62°F to 72°F, the heater supplies the water at 3.5GPM, and in less than 62°F, it provides the water at the rate of 3GPM on an average.
The digital thermostat is easy-to-read, and it allows you to select the temperature between 86°F to 140°F. You can change the temperature using the dial with the frequency of 1°F.
The Steibel Eltron helps you to save 15-20% energy. Installation of this tankless heater is easy. If you are new, it is advisable to call an expert. The model needs 2 circuits and 240kW at 240V.
The product is very durable, and the dimensions of the heater are 21x 20x 9.6 inches. It comes with 7 years leakage warranty and 3 years parts warranty.
What we like
- It comes with a 7 years warranty.
- It is capable of serving hot water at the rate of 5GPM.
- The digital thermostat gives you real-time data.
- The Advanced Flow Control serves hot water even when multiple faucets and showers are running.
What we don’t like
- Not suitable for hard water.
EcoSmart is on the mission of providing the durable tankless water heater from north to south of the U.S. Ecosmart 36 is one of the best products in the tankless water heater market.
This heater has the capacity of providing hot water anywhere between 3-8 GPM, depending upon your location. Let me explain to you in detail what flow rate of water you will get when you install the EcoSmart 36.
If you live in a northern area where the water temperature is below 40°F, you can get a flow rate somewhere between 3-4 GPM. If you reside in the southern U.S., where the water temperature is moderate, you can receive a flow rate of 6-8 GPM.
On a 3-4 GPM, you will be able to run 2 showers simultaneously. Whereas on 6-8 GPM, you can run 2 showers, dishwasher, washing machine all of them simultaneously. The heater requires only 0.3 GPM water activation.
The digital thermostat is similar to what we have seen in the Rheem RTEX series tankless water heaters. You can change the temperature from 80°F to 140°F with a frequency of 1°F by rotating the dial. You can even change the temperature scale by pressing the dial for 3 seconds.
I liked one thing about this heater is self-modulation technology, which saves money on your utility bills. Installation of the heater is simple, but you still need to call the expert. If anything wrong will happen, then you can lose the warranty.
It is recommended by the manufacturer to use 4 double pole circuit breakers.
The product is lightweight as it weighs about 18.35 pounds. The highlight of this electric tankless water heater is it comes with a lifetime warranty.
What we like
- It comes with a lifetime warranty.
- It weighs only 18.35 pounds.
- Self-modulation technology reduces the use of energy.
- It is easy to set the temperature of the heater.
What we don’t like
- It is not suitable for big homes if you live on the northern side of the country.
Rheem is the most famous brand all over America. This is our 3rd RTEX model out of the top 7 tankless water heater. This gives you an idea of how popular the Rheem brand is among Americans.
The RTEX-18 is a mid-size compact model that delivers instant hot water at the rate of 4.4 GPM. Space-saving and lightweight design allow you to install it anywhere you want. The heater weighs only about 14.8 pounds, making it ideal for small houses, RV, condos, offices, boats, etc. The dimensions of the product are Hx Wx D 18-1/4x 14-1/2x 3-1/2 inches.
With 4.4 GPM, you can run 2 showers and 1 faucet easily or 1 shower and dishwasher or washing machine. The heater is made of rugged brass and copper that ensures the longevity and durability of the product.
Like all other Rheem RTEX models, this gives the hard water ranging from 80°F to 140°F. The digital thermostat is equipped that allows you to change the temperature at the frequency of 1°F simply by turning the dial. The LED display shows the temperature in Celsius and Fahrenheit both, and you can change by pressing the dial for 3 seconds.
The RTEX-18 comes with a clearly defined user manual for DIYers. Like RTEX-24, this electric tankless water heater also has a 3/4 inch NPT connection in the bottom to connect the waterline. The model requires amp breakers of 2x40A, 240 Volts, and a wire of 8AWG to run perfectly.
The model has an energy efficiency of 99.8% because of self-power adjustment technology. The tankless water heater comes with a 5 years limited warranty.
What we like
- It is capable of giving a water flow of 4.4 GPM.
- It weighs only about 14.8 pounds.
- It has an energy efficiency of 99.8%.
- Easy to install.
What we don’t like
- It takes 20-30 seconds for a water heater to serve hot water during cold weather.
Rheem is one of the renowned manufacturers of water heaters, and for nearly 100 years, they are providing quality and durable products to the world. The RTEX-13 is a small compact model specially designed for small houses.
Rheem RTEX-13 is not only suitable for home but RV and boat too. The compact model is super light as it weighs only 8.5 pounds. As it is small in size, you can fit it under the sink, in the closet, or anywhere. The dimensions of the water are Hx Wx D 12-5/8x 8-1/4x 3-5/8 inches.
The best part is it requires only 0.3 GPM to activate the heating components. It supplies instant hot water at the rate of 3.17 GPM to run 1 shower and 2 faucets. The model has brass and copper immersion.
The self-modulation adjusts the power as required, thus making this electric tankless water heater very energy-efficient. Like other RTEX models, this one provides hot water ranging from 80°F to 140°F, with the frequency of changing at 1°F. The digital thermostat is easy to understand and adjust the temperature. You can also change the temperature scale by simply pressing the dial for 3 seconds.
Installation is pretty easy, and you don’t need to call experts. It comes with everything you need. It has a 3-ft long electric cable, a 1/2 inch NPT adapter, and a 1/2-inch side compression water heater. The model requires amp breakers of 60 Amps, 240Volts, and a wire of 6 AWG to run perfectly.
This electric tankless water heater is not suitable for homes that are in colder climates. The RTEX-13 heater comes with 5 years limited warranty.
What we like
- It weighs only 8.5 pounds.
- Ideal for small homes, RV, and boat.
- Easy and simple installation.
What we don’t like
- Not suitable for more than 4 family members.
- It will not work in colder climates.
This is the second product from EcoSmart we have added to our review. EcoSmart ECO 11 is a small water heater for a family of 3-4 people.
It is lightweight as it weighs only 6.5 pounds, and its smaller compact size lets you install it anywhere in the house, even in the closet. The dimensions of the product are 11.5x 8x 3.75 inches.
As the tankless water heater works on electricity, it doesn’t require ventilation like the gas heater. It has a capacity of supplying hot water at the rate of up to 2 GPM.
The self-modulation system measures the flow and temperature of the incoming water. It changes the heating accordingly to provide your desired water temperature. This factor helps you save hundreds of dollars in a year on the utility bill, and it has an impressive energy efficiency of 99.8%.
It has a temperature range between 80°F to 140°F with the interval of 1°F, and the heater works best when the water temperature is above 67°F. It allows you to adjust the temperature via dial, and you can also change the temperature scale by pressing the dial for 3 seconds. This is one of the best electric tankless water heaters, but it is not suitable for cold climates.
One thing we don’t like about EcoSmart is that you need to call a certified plumber to install it even though you are completely capable of doing it all by yourself. The reason is you may lose the warranty if you install it all by yourself.
Like other EcoSmart tankless water heaters, it also comes with a lifetime warranty.
What we like
- It comes with a lifetime warranty.
- It only weighs 6.5 pounds.
- You can set the water temperature between 80°F to 140°F.
- It has a higher energy efficiency of 99.8%.
What we don’t like
- It is not suitable for larger families.
Rheem is one of the leading brands in the U.S. and Canada for the water heater. Rheem RTX-24 is an electric tankless water heater with an energy efficiency of 99.8%. With an energy efficiency of almost 100, it is the most efficient electric water heater currently available in the market.
The water heater has a capacity of providing instant hot water of 6 GPM. It is ideal for small families as well as large families. You can run 2 showers and a dishwasher or washing machine at the same time.
Space-saving design allows you to install the small yet efficient water heater anywhere, even in a small space area. It is lightweight as it weighs only about 18 pounds so that you can install it on the wall without any difficulty. It uses 3/4 inches NPT connection to connect to the main water line. The dimensions of the water heater are 18-1/4 x 17-5/8 x 3-1/2 inches.
The model requires amp breakers of 3x40A, 240Volts, and a wire of 8 AWG to run perfectly. It provides hot water ranging from 80°F to 140°F, and you can change the temperature with the frequency of 1°F. The stylish digital thermostat control with an LED display shows the temperature, and you can even convert it into Celcius by pressing the dial for 3 seconds. This product surely offers the value of money.
The water heater does not have a built-in water softener, so you need to purchase it separately if your house has hard water. The 3 copper immersion heating elements are serviceable and advanced self-modulation adjust power as per the demand. The product comes with a 5 years warranty.
What we like
- Comes with an energy efficiency of 99.8%.
- Easy to install and only weighs 17.8 pounds.
- LED display to set temperature.
- Supplies on-demand hot water up to 6GPM.
What we don’t like
- It does not have a water softener.
Benefits of Electric Tankless Water Heater
The benefit of having an electric tankless water heater is much more than the tank water heater. The benefits are:
Need less space:
As in the name, the tankless heater does not need the tank to store the water. They supply hot water on demand. The electric tankless water heater is compact in size and can be installed anywhere in the house, even in the closet. You can also install the water heater outside, but you would need the UV protection cover.
Save lots of energy:
Electric tankless heaters are the most efficient water heater available in today’s market. They are known to save hundreds of dollars every year on utility bills. Some expensive water heaters are known for providing higher energy efficiency of 99.8%. The simple reason is they only consume energy when someone opens the faucet, and on the other hand, the traditional style heater runs the burner continuously to keep water warm.
Higher life expectancy:
The average life of a traditional water heater is 8-10 years. In comparison to the tankless water heater, it is too low. Traditional heater works perfectly up to 10 years, whereas the tankless water heater comes with a warranty period of 10 years, and some of them like the EcoSmart water heater come with a lifetime warranty.
The tankless electric water heater easily lasts for 15-20 years, and if proper care is taken, it can efficiently work up to 25 years.
Tankless water heater requires minimal maintenance every 3-4 years. You don’t need to call experts; you can do it all by yourself. In comparison, the tank water heater requires maintenance every year, and if you live in an area with excess hard water, you are forced to do maintenance every 6 months.
Initial and Installation Cost:
Tank water heaters are cheaper than the tankless water heater. But the installation cost is high, and you also need enough storage to fit the tank. Electric tankless heaters are less expensive than gas tankless water heaters. The installation cost of the electric unit is less than the gas one. Moreover, the installation is pretty easy than the gas unit.
Another thing we need to consider is the electric units are more efficient than gas tankless heaters.
Types of Electric Tankless Water Heater
So, you have decided on the electric tankless water heater over the gas unit. But your search is not over here; there are various types of electric tankless heaters available in the market, and you need to choose which one is suitable for you. The types of heaters are:
Whole-house electric tankless water heater
The whole house water heater is designed to provide hot water in every tap of the house. Whether you are planning to take a shower or running a dishwasher, hot water is important. An electric tankless heater provides instant hot water.
The tankless heater with a capacity of providing 4-5 GPM is suitable for a family of 4, and as the family members increase, so does the capacity of the water heater.
Portable electric tankless water heater
Portable electric tankless water heaters are compact and lightweight and can be carried anywhere. Compared to the whole house, they have a much lower flow rate.
A portable electric unit is ideal for camping, RV, boat, etc. If you need hot water only for a bathroom, instead of wasting a fortune on a whole house tankless water heater, you can go for a portable electric tankless water heater.
They are cheaper than the whole house water heater.
Point of use or under the sink electric tankless water heater
Point of use tankless heaters are also very useful like whole house and portable tankless heaters. They are ideal for one faucet or one shower. You should consider this kind of electric tankless water heater if you only want hot water from one faucet or shower.
This is also ideal for someone who has a tank water heater but not able to get enough hot water.
What size electric tankless water heater do I need?
You need to figure out the required water flow before purchasing an electric tankless water heater. To figure out the required water flow, you need to consider some of the usages like a number of family members, number of bathrooms, dishwashers, washing machine, etc.
If you choose the small size, you may end up disappointed, and one of the family members with cold water when more than 1 shower is running simultaneously, and for bigger than the required size, you will end up paying a higher amount.
The showerhead requires a flow rate of 2GPM, the dishwasher also needs 2GPM, the Washing machine needs the water flow between 2-2.5GPM, and the faucet needs 1 GPM.
You can determine how many things you want to run simultaneously and add the GPM to know the flow rate for your house. For example, you are planning to run 2 showers and a washing machine altogether; then you need an electric tankless water heater that produces hot water at the rate of up to 7 GPM.
The next step is to determine the required temperature. Groundwater temperature depends on the area where you live. For example, you live in an area where the groundwater temperature is 50°F, and the desired hot water is 115°F, then you need a temperature rise of 65°F.
You can easily obtain the groundwater temperature of your city on Google or by contacting the local water department.
Why Buy an Electric Tankless Water Heater?
Buying an electric tankless water heater has its own benefits over the traditional tank heater. An electric tankless water heater can be installed anywhere inside the house, even in the closet. In the case of a tank water heater, you need a special storage area for the tank.
When multiple faucets are running on the tank water heater, tracking the usage is difficult, and you can end up using all hot water. Tankless heaters are designed to provide hot water on demand and capable of providing endless hot water. With an electric tankless water heater, you don’t need to worry about the usage and can run multiple faucets, appliances all at once without any worry.
We agree with you on the initial cost that tankless heaters cost more than the tank water heater, but they save hundreds of dollars on utility bills every year. Installation charges of gas water heaters are high compared to the electric tankless water heater because the gas unit needs an additional line of natural gas or propane gas.
Another reason is life expectancy; the lifespan of a tank water heater is 8-10 years max., whereas the life expectancy of tankless heaters is 15-20 years, and if proper care is taken, it will work efficiently for 25 years.
Annual maintenance is required for a tank heater, and in hard water, maintenance is required every 6 months. The tankless heater requires maintenance every 3-4 years.
Things to consider before buying Electric Tankless Water Heater
Before making a purchase decision, you need to consider a few points to choose the perfect electric tankless water heater for your house. Things to consider when buying an electric tankless water heater are:
Flow rate requirement is dependent on the number of faucets and water-using appliances you are planning to use simultaneously. The showerhead and dishwasher need 2 GPM, and the washing machine needs between 2-2.5GPM.
To understand this clearly, let’s say you are going to run 2 showers simultaneously. So, you will need a heater that is capable of producing heat water up to 5GPM. If you add a dishwasher to the list, then the required GPM would go up to 7 GPM, and you will need to purchase the tankless heater that supplies hot water at the rate of up to 7 GPM.
Make the list of appliances you wish to run and add up their GPM. You will get a clear picture of how much flow rate your house needs. To read in-depth about the flow rate, visit this section: What size of electric tankless heater do you need?
GPM stands for the Gallons per Minute. The heater with the GPM rating of 7 will supply hot water at the rate of 7 GPM. So as we discussed in the flow rate, you need to determine how much GPM supply you want.
Groundwater temperature also plays an important role in determining the GPM rate. If you live in an extremely cold area where the groundwater temperature is below 38°F, then it will take more time to heat the cold water, and you will end up receiving a lower GPM. If you live in a cold region, then it is advisable to purchase a heater that produces more GPM than your desired.
Compared to the tankless gas unit and traditional tank unit, installing an electric tankless water heater is quite easy. Since it does not emit poisonous gas like a gas tankless heater, you don’t need to install the additional vents. You can even install the compact size electric tankless heater in the closet.
Installation cost is very cheap for an electric tankless heater, but if your home electric system is not capable, then you need to upgrade the whole house electric system, and it ain’t cheap. Compare the required energy of the model with your current home electric system and consult with an electrician for proper guidance.
Indoor VS Outdoor:
You can install an electric tankless water heater inside the house or outside the house as well. The installation place of the heater is dependent on the plumbing system of the house.
If it is possible to install it inside, then you can install it in any place of the house. If you are forced to install it outside of the house, then you don’t need to worry because the product is durable and capable of withstanding the rain, wind, and any other kind of rough weather.
Although if you reside in a colder region, then make sure the water does not freeze inside the pipe. It has a built-in heater to keep pipes warm, but in case of a power cut, drain the rest of the water out of the pipe.
Out of all types of water heaters available out there in the market, the electric tankless water heaters are more energy-efficient. Advancement in technology reduced the power consumption drastically of electric tankless water heaters.
The electric tankless heater helps you save hundreds of dollars on utility bills. There are many haters out there in the market that have an energy efficiency of more than 99%. Of course, they are expensive, and if your budget is low, you can go for a heater that has an efficiency of more than 96%.
Another thing you need to consider is the electric system in your house. We covered that topic installation point but still make sure that the current electrification of your house can supply enough power to the water heater. If your house’s current system is not capable, then you must upgrade before purchasing the electric tankless water heater.
1 kW is equal to 1000 watts. It is a metric unit to measure the energy consumption by the appliance. A higher kilowatt in electric tankless water heaters means higher wattage appliances will get. Further, the electric tankless water heater with high wattage will consume more power and increase the utility bills, which means less saving.
To avoid these consequences, evaluate which appliance consumes how much power and how often you are going to use that. If you are going to use high power appliances very less, then you can go for a lower wattage rating and save some money on the tankless water heater, and increase your savings on bills.
The warranty period on the tankless water heater is higher than the standard tank heater. A manufacturer like EcoSmart gives a lifetime warranty on the heater, whereas other manufacturers give a warranty period of 10 years.
Before making any buying decision based on a warranty, read the warranty policies of the product. For example, some models come with 10 years leakage warranty and 3 years parts warranty. Some manufacturers cover everything for 10 years.
Many manufacturers prefer that the heater must be installed by a certified expert and failing so can cost you your free warranty. Installation costs increase as you need to pay an expert as well.
Q. How to install an electric tankless water heater?
Many manufacturers insist that the installation of electric tankless water must be done by experts. But if you still want to install it all by yourself, then it is an easy process.
Mount the system into the wall using bolts and screws. Shut the water valve off and join the pipe of the main connection using the Teflon tape to the system. Connect the other pipe that is going to supply to the whole house to the hot water outlet of the system.
The next step is to supply electricity. You need to install the sub panels that have their own circuit breakers right next to them so you can disconnect easily when needed. Run wires into the subpanel and then into the unit.
Make sure the heater is off all time.
Q. What are the benefits of an electric tankless water heater?
Electric tankless water has more benefits than the conventional tank heater. It saves more space, supplies endless hot water, and decreases the utility bill.
Further, it requires less maintenance and has a high life expectancy of more than 15 years. To learn more about benefits: Visit our section on the benefits of the electric tankless water heater.
Q. How does an electric tankless water heater work?
When you turn on the faucet or shower, the burner or heating components inside the water heater activates. The unit heats the water as it passes through the system.
When you turn off the faucet or shower, it will automatically turn off the unit.