Top 13 Best Hot Water Heaters 2021 Reviews

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If you are looking for the best hot water heaters, you better catch up with the available options first. The market houses so many of them and you get to choose whichever option you want. Some heaters are tank-less and then you have others with mini-tank, which can fit right under your sink. Some of the major brands you can trust for their water heaters are Rheems, Rinnai, Eemax, Stiebel Eltron and so much more.

Make sure to pre-set a budget as that helps you to choose the right water heater for your use. Furthermore, the heater for residential purposes will differ from the one under the commercial head. So, be sure to get that point straight as well, whenever you are looking for the ultimate water heater in here. Listed below are the best hot water heaters options to choose from. See our recommendations Best Water Heaters and Best Tankless Water Heaters.

Comparison of Table

Best Hot Water Heaters

Below are the Best Hot Water Heaters to buy in 2021.

#Tankless Electric ECO TOUCH Hot Water Heater

Taking a bath in lukewarm water after a tiring day at work will surely rejuvenate your body and relieve you of the tensed muscles. It is true that you need a proper hot water tank for the same purpose and you can get it from Tankless Water Heater Electric ECO TOUCH 9KW 240V.

You will receive instant and even sufficient hot water. It comes with a 9kW heating system, where the heater gets to supply endless hot water of around 116 degrees. There is no waiting time for preheating the tank-less heater or even do not have to think about the temperature fluctuations.

It is that perfect companion for sinks and will bring in that ultimate relaxing and comforting feel to it. The product further comes with smart self-modulation. This water heater can adjust power input, depending on the temperature setting and flow rate, designed in real-time.

With the reduction in water flow, the power input decreases and can help you get the comfortable and ideal temperature in place of just scalding hot water. You will further receive optimal energy efficiency by around 99.8%, to save the electricity charge every year.

This hot water heater comes with digital display and touch control panel.

Tankless Water Heater Electric ECOTOUCH 9KW 240V on Demand Water Heater Self-Modulating Instant Hot Water Heater Point Of Use Water Heater ECO90 Black


  • Instant hot water service
  • Smart self-modulation service
  • Micro-computer control 
  • Patent heating technology
  • Comes with various protection devices
  • 116℉or higher temp
  • Digital display
  • Approval by ETL

  • Easy to install.
  • Stylish to look at.
  • Durable.

  • It has a small capacity of holding water at one time.

#Rinnai RLX Series HE Tankless Hot Water Heater

For that ultimate indoor heater, you have the Rinnai RLX Series HE+ Tankless Hot Water Heater by your side. For your entire home, now you get the opportunity to enjoy endless hot water. You have efficient rankles hot water heater running on natural gas.

This hot water heater comes with indoor installation services. This product is known to have around 9.4 GPM hot water flowing rate, which is subject to vary based on the groundwater temperature.

You have the Circ-Logic technology, which will help you to set some of the recirculation patterns, which can always coincide with the typical based habits right now. You will receive hot water whenever you feel the time is right. Just make sure to learn more about the range and then pre-set your budget accordingly.

It comes with a residential factory warranty of 120 months on the heat exchanger, 12 months on labor and 60 months on the parts. The tank-less hot water heater comes with ThermaCirc360 technology, which helps in recirculating hot water through pipes just to help you get it on time without wasting much.

Rinnai RLX94iN RRLX94iN, 9.8 GPM, Indoor Installation


  • ThermaCirc360 technology
  • Compact design to save valuable space
  • Endless hot water
  • 9.4 GPM flow rate
  • Perfect for indoor installation only
  • Warranty on the heat exchanger for 120 months, 12 months on labor and 60 months on parts

  • Perfect fit for every bathroom size.
  • Durable.
  • Great customer service.

  • Cannot install it outdoor.

#Eemax EEM24027 Electric Tankless Water Heater

Eemax is all set to present its wide-ranging customers with the best EEM24027 Electric Tankless Water Heater, designed to last long. Available in blue color, this tank-less water heater will present a continuous supply of promising hot water.

It will heat up the water that you need only and whenever you need it. You will always receive consistent, instant and even endless hot water. This heater is known to use the self-modulating and advanced technology available.

It means that the unit will get the chance to adjust the energy level that it might need to be input, depending on the amount of hot water you need. There are always compact sizes available just because you want to store it within your available space.

However, it is always recommended to verify the size of the machine and measurement of your place, before making the right call. This product is perfect for not just residential use but for covering commercial water heating needs as well. With 27 kW unit and 240 volts of power, it can power up 1 shower and 2 sinks at the same time.

Eemax EEM24027 Electric Tankless Water Heater, Blue


  • Endless hot water
  • Perfect for residential or commercial needs
  • 27kW unit with 240 volt
  • Advanced and self-modulating technology
  • Compact sizes for every perfect fit
  • 5 years warranty for leaks and 1 year for parts

  • Great  quality.
  • Energy efficiency.
  • Great customer service.

  • No cons.

#Rinkmo Electric Tankless Hot Water Heater 

This hot water heater is believed to be a fantastic option compared to the conventional electric water heater. You will have hot water in the bathroom, even if you shower for a long time. You do not need to encounter the challenges of preheating. Because of the 3s, you will find hot water, as per your needs.

It is ruling the industry as people have reviewed that they do not face any annoying delays in getting hot water. It is a superb option for running the dishwasher and showers without any challenges. You will be capable of running two showers and three faucets at once by purchasing this model.

It is excellent for homes in the Southern United States, Canada, and the Northern United States, where the demand for hot water increases. Smart flow sensors and temperature sensors of high quality are integrated into this unit, assuring a great comfortable experience. Thus, you will find the temperature as stable as you reduce the low water pressure and flow rate.

Another prominent reason why users are happy after using this unit is that the water’s temperature will not fluctuate while taking a shower. Besides this, it is a safe choice for your family members as it includes an auto protection feature. As the outlet’s temperature reaches almost 167 degrees F, the system will cut off automatically so that you can enjoy a safe shower.

Because of the compact design, you can install it in different non-traditional spaces like a basement, utility room, attic, garage, crawl space, and closet. The digital temperature display of this unit is easy to read, and hence you do not need to think about complicated installation requirements.

The product will be turned on only when hot water is necessary. So, it is practical in saving about 50 percent of water heating costs. It can be a fantastic option for usage at home and different commercial places where endless hot water is required instantly. So, you can buy it for the beauty salon, barbershop, apartment, gym center, to name a few.

The smart design of this tank heater also enchants this unit. It has sheet metal shell construction which is resistant to fire. The screen of this product displays the original outlet water temperature, in place of the set temperature. The machine of this unit auto stops as no water gets heated.

RINKMO Electric Tankless Water Heater 18KW 240V Instant Residential Electric on Demand Water Heater for Bathroom Bathtub rv Whole House and Point-of-Use Shower Sink Small


  • 18KW 240V Instant Hot Water Heater
  • Shell metal shell construction
  • Digital temperature display
  • Cleanable filter
  • Smart flow sensors
  • Temperature sensors

  • Small size.
  • Auto protection.
  • Well sealed packaging.

  • No cons.

#Biselong Electric Mini-Tank Hot Water Heater

This hot water heater features stainless steel construction, and thus it does not rust easily. It also has an anti-leakage plug. The presence of the several safety protection features safeguards the members of your family from leakage, scald, and the injury. In addition to this, you can ensure that this unit’s premium plastic shell is resistant to corrosion.

It is believed to be the perfect choice for bar, kitchen, community, hospital, school, and R.V. It has 2.5 gallons storage, and hence you can be ensured that it fits beneath the sink for enjoying hot water, as per your requirements. The thermal efficiency of this unit is about 98 percent.

It has a maximum temperature of about 167 degrees F. It is decked with a built-in smart chip that heats the water to the temperature you want and insulates automatically once water is heated to the desired temperature. The company offers a 1-year warranty.

Other features that have given this product a special place in the heart of the potential audience are the vent valve, knob temperature adjustment design, pipes, tee pipeline, and different accessories that make installation fast without the extra expenses. You will need about 8-15 minutes for heating water to the required temperature. 

110V-120V Electric Mini-Tank Hot Water Heater Storage,1.5KW Kitchen Household Compact Size Point-of-Use,Rv Hot Water Output of 2.5 Gallon, 1 PCs 16” Long 1/2”FIP Stainless Steel Water Hoses


  • Stainless steel construction
  • Maximum temperature 167℉
  • Knob temperature adjustment design
  • Vent valve
  • Built-in smart chip
  • Anti-leakage plug
  • Voltage: 120V~50Hz
  • GFCI Plug
  • 1-year warranty

  • Great quality.
  • Easy to control.
  • 24 hours of customer service.

  • As per some users, water started leaking from the front cover, after installation.

#Noritz NRC71DVNG Indoor Condensing Direct Vent Tankless Water Heater

It is one of the best in the class tankless hot water heater, bringing a built-in controller and advanced heat exchanger design. You can experience the highest water flow rate with a speed of about 7.1 gallons of water every minute.

You will get a power cord of 6 inches by investing in it. You will get unlimited hot water by installing this product in your home. The space spacing and compact design of this unit invoke interest among people to go for it, instead of other models.

Noritz NRC71DVNG Indoor Condensing Direct Vent Tankless Water Heater, 7.1 GPM - Natural Gas


  • Up to 7.1 gallons per minute
  • 6 inches power cord
  • Built-in controller
  • Advanced heat design
  • Low Nox

  • High efficiency.
  • Space-saving.
  • Unlimited hot water.

  • Some users had a horrible customer service experience.

#Stiebel Eltron Tankless Hot Heater

A perfect tank-less heater from Stiebel Eltron, this Tempra 36 Plus runs on electricity and comes with on-demand hot water. It comes in 12 different styles, making it easier to choose one as per your requirements. You will receive an on-demand and unlimited supply of hot water, which is why more and more people are getting this water heater for their daily use.

The sleek design is perfect for saving some space and there is no need to work on vents as well. Then you have the electronic switch, which gets activated for the virtually silent based operation here. It has a single phase of 60 Hz with a voltage of 208 V and even wattage of around 27 kW.

You have the copper sheathed based heating element, which is perfectly housed in the copper cylinder. This product comes with 7 years of leakage warranty and 3 years of parts complete warranty. Using this tank-less water heater will definitely help you save energy thanks to 0.99 EF and without any standby losses and with the self-modulating technology.

Stiebel Eltron Tankless Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White


  • Self-modulating technology
  • Digital display
  • Pre-set temperature buttons
  • Water flow and savings monitor
  • Advanced form of flow control
  • Total silent operation
  • Constant energy saving
  • 7 years of leakage warranty
  • 3 years of parts warranty

  • Great design.
  • Durable.
  • Easy to use.

  • It fails to work with 200 amps.

#Takagi T-H3J-DV-N Condensing Natural Gas Indoor Tankless Water Heater

With a higher capacity of 6.6 gallons per minute, this Takagi T-H3J-DV-N High-Efficiency Natural Gas Indoor Tankless Hot Water Heater is one that most people aim towards. Now, you get the chance to enjoy endless hot water whenever you want. Even the compact and space-saving size of the product makes it a vital choice among masses.

Another interesting point to consider will be the energy conservation service, which is perfect for your daily use. There are computerized features available, which ensure safety as the number one choice. There is no pilot light that you need to focus on as well. 

Furthermore, this machine is likely to satisfy the much-awaited 2012 SCAQMD Rule 1146.2, which is designed to talk about the ultra-low based NOx emissions. So, this tankless water heater is perfect for taking care of the environment as well.

It comes with 160,000 BTU gas input, designed to produce enough hot water in two bathrooms during summer months and 1.5 baths during winter. 

Takagi T-H3J-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater, 6.6-Gallon Per Minute


  • Ultra-low based NOx emissions
  • On-demand hot water always
  • Energy conservations
  • Safety features maintained in a computerized manner
  • No pilot light
  • 160,000 BTU gas input
  • 5 years limited warranty on parts and 1 year on labor

  • Space Saver.
  • Compact design.
  • Long-lasting.

  • Takes some time extra to warm up water.

#Rheem 240V 3 Heating Chambers RTEX-24 Tankless Water Heater

Rheem is known to provide some of the best tankless water heaters to the world out, and right now, you can try out 240V 3 Heating Chambers RTEX-24 Residential Tankless Water Heater. This product is known to come handy with external digital thermostatic control.

This tankless water heater comes with an LED display with ultimate accuracy. When you are looking for self-modulation machines, this one is the right for you. Now you can adjust power as per your choice for meeting the demand for hot water.

This water heater comes with a durable version of copper immersion three heating elements. If you need it, you can get field service as well. The installation procedure is pretty simple with the bottom ¾ inch associated with the NPT water connections.

The items are well-threaded for that easy replacement. The flow rate will be around 5.9 GPM. The copper immersion element comes with brass top, which increases the longer working life and well-threaded for that easy replacement. 

Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray


  • Flow Rate: up to 5.9 GPM
  • On-demand hot water
  • Temperature control with advanced self-modulation
  • 99.8% energy efficiency
  • Robust copper immersion-based heating
  • Digital display of temperature
  • Simple installation with NPT water connections
  • 1 year limited warranty

  • Stylish.
  • Easy to install.
  • Takes less time to produce hot water.

  • No cons.

#Ariston Andris 8 Gallon 120-Volt Mini-Tank Electric Water Heater

Ariston is yet another name whenever y oar thinking about manufacturers of the mini-tank water heater. You are cordially invited to try out the Andris 8 Gallon 6 Year 120-Volt Point of Use Mini-Tank Electric Water Heater from the same house, and won’t regret making this choice.

It is primarily available in 3 sizes and the prices will vary based on the size you have chosen, with the minimum being 2.5 gallons and 8 gallons as the maximum one. It is a compact designed hot water tank, which will provide you with hot water whenever you ask for it.

It has 6 years of limited warranty on tank and 2 years limited warranty on parts. The products can be floor or wall-mounted, with rubber feet and wall brackets included in the package. It comes with a DIY installation with a 2000 watt heating element.

It helps in drawing 12 Amps and the temperature ranges between 65 Degree F and 161 degrees F. Thanks to its flexible mini size, this water heater can easily fit anywhere. The electrical connection will be hard-wired and it needs to be hardwired to the electrical system available. 

Ariston Andris 8 Gallon 6 Year 120-Volt Point of Use Mini-Tank Electric Water Heater


  • Compact mini design to fit any house
  • DIY installation
  • 2000-Watt heating
  • 65°F-161°F temperature range
  • Hard wired with a circuit breaker size of 20A
  • TitanShield to protect the inner part
  • Safe foam insulation for increasing efficiency
  • No need to deal with recirculation line
  • 6-year limited warranty on tank
  • 2-year limited warranty on parts

  • Sleek design.
  • Easy to install.
  • Great quality.

  • Relief valve not installed but available.

#Rheem MR50245 Marathon Tall Electric Water Heater

Among promising options from Rheem in terms of water heater will be MR50245 Marathon Tall Electric Water Heater, 50-Gallon. The size is perfect for covering a bigger space. The efficiency level will be ranging between 0.90 and 0.94 EF.

The recovery rate is going to be 20 Gallon GPH with a 90-degree rise. It is one thermally fused upper element, known to offer that right protection against any form of dry-firing.

You will receive a brass drain full-flow valve, which is a major part of this particular hot water tank from Rheem. There are standard replacement parts available too, which means you don’t have to invest a lot of money on these items at all.

It is a non-metallic electrical water heater. So, the item is not just durable but also light in weight. It will warranty to not leak for the rest of its working life. The blow-molded polybutene tank is really resistant to corrosion and rust as metal is not the main material for its manufacturing.

It comprises of multiple filament layers for unmatched strength. Even the Polyurethane insulation is here for reducing energy consumption.

Rheem MR50245 Marathon Tall Electric Water Heater, 50-Gallon


  • Polyurethane insulation for lower energy consumption
  • Polybutene tank, blow-molded
  • Impervious to corrosion and rust
  • Multiple filament layers
  • Recessed drain valve
  • Polysulfone dip tube 
  • Molded polyethylene outer shell
  • Lifetime warranty on tank
  • 6 years limited warranty on parts

  • Lightweight.
  • Excellent quality.
  • Less energy consumption.

  • No cons.

#Camplux ME25 Mini Tank Electric Water Heater

CAMPLUX ENJOY OUTDOOR LIFE is here to present you guys with ME25 Mini Tank Electric Water Heater with a capacity of 2.5 gallons. There are other two sizes available, one with 4 gallons and another one with 6 gallons.

The main aim of this 2.5 gallon one to use is to fit it right under the sink, so that you get the opportunity to procure hot water whenever you need to. This is one electric water heater, which is really easy to maintain. It comprises of the glass-lined tank, for that longer form of service life.

Moreover, you can’t ignore its thermostat control, which will allow the water temperature to adjust properly. Then you have high limit device, which will protect the machine from overheating. You can plug it in to a 120-volt outlet for enjoying independent installation.

You can install it in-line with a larger hot water source. The product can be mounted on floor, wall or shelf, thanks to its flexible size and smaller compact design. You can install the heater directly at the sink for getting water heated directly. 

Camplux ME25 Mini Tank Electric Water Heater 2.5-Gallon with Cord Plug,1.5kW at 120 Volts


  • 2.5-gallon tank size
  • Easy to maintain with glass-lined tank
  • Thermostat control
  • High limit device
  • Well plus into 120-volt outlet
  • 150 PSI, CSA listed pressure relief and temperature valve
  • Available in other 2 sizes, 4 and 6 gallons
  • 1 year limited warranty on water heater unit
  • 90 days warranty on accessories

  • Perfect fit under sink.
  • Easy to install.
  • Great design and sleek look.

  • No cons.

#Bosch Electric Mini-Tank Water Heater

If you don’t want to wait much for water to turn boiling in then Bosch Electric Mini-Tank Water Heater Tronic 3000 T 7-Gallon (ES8) is the one option to consider. It can be mounted on the wall, shelf or floor, whichever matches your requirements the most.

Other than the 7 gallons one, you can try out the least expensive and smaller size of 4 gallons as well. This is one convenient mini-tank, which can fit right under your sink. So, whenever you need hot water, you can get it.

You can mount the item vertically for 7 gallons of water and horizontally for 5.1 gallons of water supply. There is vertical orientation with hot and cold lines right on top of the said unit.

It comes with a reliable water source. So, it is hard-wired for providing an on-demand water source for office or home needs. It has a heating capacity of around 1440 W and the temperature will be ranging from 65 degrees F to 145 degrees F.

There will be 150 psi as operating pressure and with water fittings of ¾ inch of male NPT. You will need Amp 12A or 120 Volts as electrical requirements for this machine to work.

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 7-Gallon (ES8) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted


  • Fits right under your sink
  • Can be installed vertically or horizontally
  • 1440 w heating capacity
  • 98% Thermal efficiency
  • 6 years warranty on units and 2 years on parts

  • Great for small spaces.
  • Amazing look.
  • Easy hot water flow.

  • No cons.

Buying guide: Best Hot Water Heaters

It is recommended to analyze the below-mentioned parameters before selecting the best hot water heaters of your choice:

Tank size: The tank’s size will matter a lot while choosing a water heater. There are various options under gallons, starting from 2.5 and moving towards 50 gallons of water, as well. If you have bigger household, then the one with maximum water gallons will be the right choice. Yes, the price will differ as well.

Type Of Water Heater: The first thing to think is what type of water heater you want to use in your house: conventional tank, tankless, solar, or hybrid. If you just want something cheap to buy and install, and you are not as concerned about energy efficiency, a tank heater might be the best choice for you. If you require something that requires less maintenance, a tankless heater might be the best option for you. If you are concerned about long-term energy savings and you are not as concerned about budget, the solar heater may be the way to go. Hybrid water heaters use the heat pump to catch the heat that is in the air and transfer it to the water supply to save on energy. The purchase and installation costs aren’t as high as solar heaters. They take up a lot of space.

Fuel Source: It is essential to determine what type of fuel source you have in the cabin. Here are the differences between gas/propane, electric, solar, and hybrid fuel types.

Gas/Propane: It uses a burner to heat water. It is perfect for homes that are hooked up to a natural gas line. They are more energy-efficient fuel source than electricity. It cost more than electric water heaters in terms of initially buying the heater. They come with a size range of 30 to 100 gallons.

Electric: Electric water heater is cheaper to purchase and install in the upfront. It is substantially more expensive than natural gas and propane. They are easier to install in houses that do not have venting. The electric water heater offers a variety of high-efficiency options. They come with a size range of 28 to 100+ gallons.

Solar: Solar uses the sun’s heat to heat up your water. The heat from the sun’s radiance is absorbed by panels that sit on your rooftop. It can cut a large percentage of your heating bill.

Hybrid: It uses energy from the air and transferring it to water through electricity. They are larger than standard electric water heaters. They are more energy-efficient then electricity, ending in much lower bills. It is more expensive on front end. They come with a size range of 50 to 80 gallons.

High Efficiency and Energy Star: There are mainly two reasons to consider high-efficiency water heaters: saving bills and helping the environment. ENERGY STAR® is the trusted government symbol for energy efficiency, helping customers to save money and protect the environment. An energy factor rating regulates Water-heating efficiency. The higher the energy factor, the more efficient the heater.

Flow Rate: Flow Rate, also known as GPM(Gallons-per-Minute). It is measurement of how many gallons of water flow out of your shower head every minute. The tankless water heater doesn’t store any water.  The shower uses around 2.5 GPM, and a washing machine uses around 2 GPM. If you plan on running 2 showers at the same time, you would need a tankless heater that could deliver at least 5 GPM.

BTU(British Thermal Unit) Rating: It is important to consider the BTU rating. The BTU rating describes how much heat the water heater can transfer to the water per hour.

Power consumption: You want to purchase a water heater which won’t charge you a lot at the end of every month as electricity bill. So, while purchasing a heater, be sure to check its power consumption. If it performs strongly on lower power, that’s the right choice to make.

Self-modulating capacity: Waiting a long time for hot water is not the ideal situation while checking in with a water heater. So, look for the ones with Self-modulating capacity. This advanced technology will make the machine work super-fast, and provide you with hot water right on demand.

Price matters a lot: Not everyone is comfortable in spending a hefty amount for purchasing a water heater. So, remember to check the price of multiple products before taking the final call. Depending on the product and its features, the prices will vary. The one with lower gallon count will cost less. Keep that point too. 

Protective devices: Be sure to head for a water heater with extra protective shields for maintaining safety. Some offer multiple filament layers for extra protection. You can further get a blow-molded polybutene tank to make the item free from rust and corrosion, just like Rheem MR50245 Marathon Tall Electric Water Heater. So, don’t forget to check this option as well, before taking a final call.

Warranty period: Always check-in for the water heater with a great warranty period. The warranty for the main unit will differ from the parts. So, always check in with the best manufacturing unit, offering a minimum of a 1-year warranty on the main unit and some warranty period for the parts .some companies can offer 6 years of warranty on the main unit like the Bosch Electric Mini-Tank Water Heater Tronic 3000 T 7-Gallon.

FAQs(Frequently Asked Questions) Hot Water Heaters

How long do hot water heaters last?

The life span of a hot water heater is around 8 to 12 years.

How frequently should you flush a hot water heater?

Most households should flush their hot water heaters every six months.

What is the perfect water heater temperature setting?

Most hot water heaters come pre-set at 140 degrees. The Department of Energy recommends setting it to 120 degrees.

How to drain the hot water heater?

In order to drain the hot water heater, follow the below steps.

  • Turn off cold water supply valve
  • Turn off the water heater fully
  • Attach the standard hose to drain valve
  • Open nearest hot water tap
  • Open the drain valve
  • Close the drain valve, remove the hose, and turn on the water supply.

How long does it take to empty a hot water heater?

You can expect the tank to empty in around 5 minutes.


Whether you are looking for the basic water heater from RHEEM or want the exclusive one from Rinnai, the final choice is yours. It is highly recommended to go through all the available options and then take the final call. It will take some time to address the best one, but all your research time and invested money are worth it. If you are looking for Best Hot Water Heaters of the best quality, you can pick one from either of the above-mentioned products without a shred of doubt.

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