Best Tankless Hot Water Heater-Reviews & Buyer Guide

There’s nothing worse when you are taking a shower, and you’ll find hot water.  Best tankless water heaters give you relief from this headache in your home by delivering instant hot water any time when you’ll open the faucet. In addition, the best-rated tankless water heaters are more compact, energy-efficient, and user-friendly than traditional bulky storage tank water heaters.

Traditional bulky tank water heaters store around 20 to 70 gallons of water, which seems like much water. When someone opens a faucet, tankless water heaters detect it and supply hot water on demand with electric or gas power.  Best-rated tankless water heaters can handle an endless supply of hot water. When you open a hot-water faucet, it’ll deliver unlimited amounts of hot water while still being relatively energy efficient.

Quick hot water Quick hot water
Bosch Electric Mini-Tank Water Heater
  • Power : 1440W
  • Temperature: 65-145°F
  • GPH : 6.8
  • Installation : Easy
  • Energy Efficient : 98%
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Self Modulating Technology + Top-Pick Self Modulating Technology + Top-Pick

Ecosmart ECO 18 Electric Tankless Water Heater


Ecosmart ECO 18 Electric Tankless Water Heater
  • Power: 27000W
  • Temperature: 80-140° F
  • GPM : 2.7-6.5
  • Installation : Takes time
  • Energy Efficient : Yes
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Buyer’s Choice+For small families Buyer’s Choice+For small families

Rinnai V65iN Tankless Hot Water Heater

Rinnai Indoor Tankless Hot Water Heater / V65iN
  • Power : 13000W
  • Temperature: 80-140° F
  • GPM : 2
  • Installation : Easy
  • Energy Efficient : 99.8%
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Portable +Safe+ Best Budget Portable +Safe+ Best Budget

Stiebel Eltron Tankless Heater

Stiebel Eltron Tankless Heater – Tempra 36 Plus – Electric
  • Power : 12000W
  • Temperature: 46-114.8℉
  • GPM : 1.58
  • Installation : Outdoor installation
  • Energy Efficient : Yes
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Self-Modulating Power Technology & Advanced Flow Control Self-Modulating Power Technology & Advanced Flow Control

Hike Crew Portable Propane Water Heater & Shower Pump

Hike Crew Portable Propane Water Heater & Shower Pump
  • Power : 29000W
  • Temperature: 86-140°F
  • GPM : 2-4
  • Installation : Easy
  • Energy Efficient : 99%
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Multi-Point-of-Use + Microprocessor technology Multi-Point-of-Use + Microprocessor technology

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater


Rheem RTEX-18 18kW 240V Electric Tankless Water Heater
  • Power : 12000W
  • Temperature: 86-125°F
  • GPM : 1.5
  • Installation : Easy
  • Energy Efficient : Yes
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Wall-mounted+LED display Wall-mounted+LED display
Rheem 240V Heating Chamber
  • Power : 13000W
  • Temperature: Adjustable
  • GPM : 3.17
  • Installation : Easy
  • Energy Efficient : 99.8%
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    Best Tankless Hot Water Heaters- Detail Reviews 

Let’s check out the detailed info on the best tankless water heaters below. Then, scroll deeper to explain how these Best rated tankless water heaters can work via a helpful buying guide and brief reviews on tankless water heaters.

1-Bosch Electric Mini-Tank Water Heater – Electric Tankless Water Heater

Bosch Electric Mini-Tank Water HeaterGas or electric tankless water heaters are usually installed in the basement or utility room to get an endless hot water supply in all your faucets and appliances around a home. However, point-of-use water heaters are seated at a specific water source. Point-of-use heaters save your time because sometimes heated water takes up to 10 seconds or more to reach all parts of the house. To avoid such delay and inconvenience, point-of-use heaters come into play.

You can use Bosch Tronic tankless water heater for three different applications, such as;

  • Use it under a single sink or shower
  • Use  it as a supplement to an existing water heater
  • You can use it for cold-water sandwiching

The Bosch Tronic 3000-tankless water heater can be installed under a sink, inside a cabinet, or another concealed location. This water heater will provide up to 4 gallons of hot water. The Bosch Tronic is considered the best-rated tankless water heater because it’ll cut down on long waits and reduce the amount of water wasted via traditional bulky water heaters.

Bosch Tronic is the best tankless water heater you need for your instant hot water needs. Bosch Tronic 3000  has a hidden mini-tank inside to supply an endless water supply. It is available in 3 different sizes; 2.5, 4, and 7 gallons. Bosch Tronic’s tankless water heater will not require professional installation. Instead, you can plug the unit into a 120v standard plug, and it’ll be ready to use.

Things we like?
  • It offers 98% thermal efficiency
  • Provides on-demand hot water within a 30-seconds
  • It’s straightforward to set up
  • Easy installation
  • It comes with a 6-year warranty on maintenance
  • 4-gallon point-of-use mini-tank fits under the sink
  • Provides instant hot water
  • Premium glass-lined material for a longer service life
Things we don’t like?
  • The warranty only applies if you get it installed by an authorized dealer

                                                  Technical Details

Product Dimensions                          13.75 x 13.5 x 13.75 inches
Item Weight                                         17.3 pounds
Size                                                        4 Gallon

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2- Ecosmart ECO 18 Electric Tankless Water Heater- Tankless Water Heater for Small Homes

Ecosmart ECO 18 Electric Tankless Water HeaterIf you are in search of a powerful tankless water heater that’ll supply your endless hot water then you are at the right place. EcoSmart Eco 18 is the best tankless hot water heater, it is powerful enough to heat up to 4.3 GPM of water. It will be enough for a household of two in warmer climates. It can also supply hot water for a single shower at a time.

EcoSmart Eco 18 is the best electric tankless heater that is efficient in its hot water supply and will not drive up your electric bill much. It self-regulates energy consumption throughout the day to save your energy cost. EcoSmart Eco has a flow sensor that’ll detect how much water needs to be heated at a given time, depending on the fixture used. Its built-in digital control allows you to set the temperature in increments of 1° from 80° to 140° F.

It has a 4 GPM capacity, maybe it will be insufficient for freezing climates. Eco 27 may be a better choice for you to get an endless hot water supply for such cases.

Things we like?
  • It weighs only 14 pounds
  • Its compact design of the ECO 18 allows it to be installed anywhere
  • The manufacturer offers a lifetime warranty
  • It is priced significantly less than other comparable models
  • Saves up to 60 of water heating costs
  • Highly durable and easy to use
  • Lifetime warranty for residential use
Things we don’t like?
  • Not suitable for larger homes
  • Not suitable for colder climates
  • Might require more than one unit

                                                Technical Details

Product Dimensions                                          3.63 x 14 x 17 inches
Manufacturer                                                      Ecosmart
Item Weight                                                        14 pounds
Included Components                                      Electric tankless water heater

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3- Rinnai Indoor Tankless Hot Water Heater / V65iN– Natural Gas Tankless Water Heater

Rinnai V65iN Tankless Hot Water HeaterRinnai V65IN is ideal for small or mobile homes, available in a mid-price appliance. When the supply water is at its optimal temperatureduring warm weather, V65IN may be able to provide up to 6.5 gallons of heated water per minute.  Rinnai Indoor Tankless Hot Water Heater can detect scale buildup will shut the appliance down rather than risk overheating damage.

If you do not have enough space in your house and want to remove the old water thoroughly, then you have the best option in the form of V65eN. It will quickly adjust the outside wall, freeing up the closet space, cutting your gas bill, and getting more hot water supply. Rinnai V65IN Indoor Tankless Hot Water Heater is suitable for homes with a single or 1.5 baths.

Things we like?
  • Offers a great supply of hot water
  • Comes with a factory warranty
  • The energy-efficient model
  • A great design that is user-friendly as well
  • No tension of greenhouse gases emission
  • Suitable for installation anywhere you want
Things we don’t like?
  • For indoor installation only
  • Might encounter a pressure drop
  • Not suitable for those on a tight budget

                                                    Technical Details

Product Dimensions                                        14.04 x 9.27 x 26.9 inches
Manufacturer                                                    Rinnai
Item Weight                                                      45.6 pounds
Voltage‎                                                               120 Volts
Water Consumption                                        6.5 Gallons

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4- Stiebel Eltron Tankless Heater – Tempra 36 Plus – Electric, On-Demand Hot Water

Stiebel Eltron Tankless HeaterStiebel Eltron Tempra 36 Plus tankless water heater is specially designed for high flow rate applications in cold climates such as America, Germany, and Canada. it will boast a 99% efficiency rating, silent operation.

Stiebel Eltron Tempra 36 Plus tankless water heater is also a popular choice for homes and commercial applications in warmer climates where very high flow demands due to multiple enormous simultaneous hot water demands.Stiebel Eltron Tempra 36 impressive max flow rate of 7.5 GPM, and 92,000 BTUs ideal in warmer climates. In addition, its bold digital display shows accumulated cost savings in the context of energy bills.

Things we like?
  • Comes with a 3-year warranty
  • Energy-efficient electric water heater
  • Temperature control makes it easy to adjust the temperature
  • Stiebel Eltron Tempra doesn’t take up a huge space
  • It was easy to install and easy to use
  • Provides saving on the electric bills
  • Parts are made of a material that is corrosion-resistant
Things we don’t like?
  • More demanding power requirements
  • A bit more expensive

                                                                       Technical Details

Product Dimensions                                    4.63 x 16.63 x 14.5 inches
Manufacturer                                                Stiebel Eltron
Item Weight                                                 1 pounds
Voltage                                                          208 Volts
Wattage                                                          27000 watts
Installation Method                                     Mounting

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5- Hike Crew Portable Propane Water Heater & Shower Pump – Propane Tankless Hot Water Heater

Hike Crew Portable Propane Water Heater & Shower PumpPeople can survive in the dirt and the sweats for a few days during outdoors tours; if you are one of those, then Hike Crew’s portable, propane-powered water heater is best for you. It combines the luxuries of home. Its built-in pump is placed into a water source and attached to a propane tank to provide ongoing hot. Hike Crew portable Propane Water Heater comes with a hand faucet, shower head attachment, and safety features.

Now you can enjoy hot, steamy water in an instant—anytime, anywhere from Portable Propane Water Heater. Aside from the automatic shut-off system, the Hike Crew unit is also equipped with a subtle safety feature. A Hike Crew propane water heater and shower unit is the perfect appliance for when you need your water heated.

Things we like?
  • Excellent control features
  • Improved safety features
  • The convenience of carrying a bag
  • Easy assembly
  • Lightweight
Things we don’t like?
  • Slightly larger than most heaters
  • Only available in grey

                                                                     Technical Details

Package Dimensions                             17.75 x 16.5 x 14.85 inches
Manufacturer                                         Hike Crew
Item Weight                                           23.9 pounds

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6- Rheem RTEX-18 18kW 240V Electric Tankless Water Heater– Electric Tankless Water Heater

Rheem RTEX-18 18kW 240V Electric Tankless Water HeaterRheem tankless water heater is a brand that represents safety and resource-saving. It is straightforward to install. Its advanced is digital thermostat can be adjusted to the exact temperature you want.

We highly recommend Rheem RTEX-18 18k to those who want to grow intent or greenhouse. You’ll like its capsule array, which makes your plants healthier, and you get better yields. It is fantastic to save space, money, and water. You can save when you resort to the right professionals and equipment.

Rheem tankless water heater will be enough to keep hot water running through your pipes nonstop for days. The thermostatic control is found on the outside. It has a digital display for you to select the desired temperature accurately.

Things we like?
  • It is small and lightweight
  • Advanced thermostat control
  • Very easy to install and maintain
  • Threading makes it easy to replace
  • Compact in size
  • Energy-efficient
  • Highly durable
  • Easy replacement & lifetime warranty
Things we don’t like?
  • It works on a relatively smaller scale
  • It cannot heat multiple showers
  • Hard to install
  • Heavy electrical requirements

                                            Technical Details

Product Dimensions                                   18.25 x 3.5 x 14.5 inches
Manufacturer                                               Rheem
Item Weight                                                 14.8 pounds
Voltage                                                          240 Volts
Wattage                                                         18000 watts
Installation Method                                    Wall Mount
Water Consumption                                    7 Gallons

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

Rheem 240V Heating Chamber RTEX-13Are you looking for a small and efficient unit that delivers standout results? Then you are at the right place; Rheem RTEX 13 is the best tankless water heater. This water heater is handy for those with limited space in their homes.

This little electric tankless water heater boasts an impressive 99% efficiency rating. It’s not the right choice for a large household. However, it’s well suited to a small home with one or two occupants. Rheem 240V Residential Tankless Water Heater is a seriously energy-smart water heater that is fast working and easy to control. This allows for massive electrical savings.

Things we like?
  • External adjustable digital thermostatic control with LED display
  • Simple installation
  • 99.8% energy efficient
  • External controls to adjust the temperature in increments
  • Threaded for easy replacement
  • Simple installation
  • Digital temperature display
Things we don’t like?
  • Unit  is not suited for a whole house

                                             Technical Details

Product Dimensions                                 12.63 x 8.25 x 3.63 inches
Manufacturer                                              Rheem
Item Weight                                                  0.01 ounces
Voltage                                                          240 Volts
Wattage                                                         13 KW

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Tankless Hot Water Heater Buying Guide

When purchasing a tankless water heater, try to Figure out which tankless water heater meets your household’s demands? And how much hot water will be consumed during peak usage? How much incoming water has to be heated to reach the desired temperature?

All these questions play an important role in determining a unit’s heating capacity and installation and maintenance costs. Here are a few key features and specifications to look out for when you are going to buy a best tankless hot water heater, such as;

Gallons Per Minute (GPM)

The GPM is the measurement of water flow, how many gallons come out of a faucet per minute from the tankless water heater.Before purchasing a tankless water heater, you must determine how much GPM of hot water your household requires. In addition, you must know how many appliances or faucets you are typically used at a time. For example, a standard shower consumes around about 2 GPM and a dishwasher around 3 GPM. If you’d like to run two hot showers and the dishwasher simultaneously, you’d need a tankless water heater that can handle at least 8 GPM. For three people, houses require around 6 GPM water while large families need at least 8 GPM.

Tankless Water Heater Temperature 

A tankless heater will produce its maximum capacity in hotter regions where groundwater temperatures are 70° or above. If you live in an area where the groundwater is 60°, and you want it to be heated up to 100°, your heater must be able to boost the incoming water temperature by at least 40°.

The actual GPM of a unit can fluctuate depending on the temperature rise needed. Manufacturers usually include a heater’s GPM capacity based on the required temperature rise in the owner’s product specification sheet. You can be downloaded temperature details from the manufacturer’s official website.

 Fuel Type of Tankless Water Heaters

Tankless water heaters can run on multiple options such as

  • Tankless Natural Gas Water Heater
  • Tankless Propane Water Heater
  •  Tankless Electric Water Heater

Tankless Natural Gas Water Heater

Tankless Gas-powered water heaters have a higher heating capacity than electric heaters.  Best Tankless Gas water heaters supply round between 8 and 11 GPM hot water.

Tankless Electric Water Heater

Electric tankless water heaters usually provide 7 GPM at most. Such tankless heaters have much lower upfront costs. Their cost will be around about $700 or less.  Best electric tankless water heaters can supply enough hot water for 4 members of the house. They are more energy-efficient than gas-powered heaters. Electric tankless heaters installation is more straightforward and cheaper as compared to gas tankless water heaters.

Electric tankless heaters might struggle to keep up in colder climates because they have lower heating capacity than their gas counterparts. As a result, their overall GPM can drastically decrease in cold weather.

                                                               FAQs Section

Which Brand Of Tankless Water Heaters Is Best?

Rinnai is the best brand of tankless water heaters.

How Do I Know Which Tankless Water Heater To Buy?

Multiple aspects will determine which tankless water heater you want to buy, such as;

  • Determine the maximum number of devices
  • Water flow rate
  • Determine required temperature rise

What Is The Lifespan Of A Tankless Water Heater?

Best tankless hot water heaters have a lifespan of more than 20 years. They also have easily replaceable parts that extend their life as well.


If you want to replace your tank water heater with the new advanced tankless water heater to save your energy bills, you need to make the switch to an instant-hot tankless water heater. The right choice best tankless water heater for your home will depend on your hot water requirements in terms of GPM and temperature rise, your budget, and the power source you want to; all such things are essential to be considered. With this in mind, the above reviews and buyers’ guides will help you find the best tankless water heater.

Being an analyst of tankless water heaters, I’ll recommend one whole-house model that would take care of your home and fulfill your water efficiently and powerfully, that is the Bosch Tronic 3000-tankless water heater. It will be installed under a sink, inside a cabinet, or another concealed location. This water heater will provide up to 4 gallons of hot water which are sufficient for small families. Ecosmart ECO 18 Electric Tankless Water Heater that is efficient in its hot water supply. It self-regulates energy consumption throughout the day to save your energy cost. 

I hope, this blog post will resolve all queries of the best tankless water heater We would love to hear your opinion regarding the best tankless hot ater heater brands or perhaps an experience you’ve had. Let us know below in the comments!


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