Best Tankless Water Heater Reviews in 2022

Tankless water heaters are a worthy investment as they provide instant hot water only when it is required, and will also save you a significant amount of money every month in lower energy bills. They do not produce energy losses that come with conventional storage water heaters. Below is a detailed review of the best tankless water heaters and other helpful information on how to choose the right one for your home.

Our 3 Top Rated Tankless Water Heaters

1. Stiebel Eltron Tankless Water Heater
1. Stiebel Eltron Tankless Water Heater
It's the best electric tankless water heater of superior quality.
2. EcoSmart ECO 27 Tankless Water Heater
2. EcoSmart ECO 27 Tankless Water Heater
If you want an energy efficient electric tankless water heater then this one is worthy option worth consideration.
3. Rinnai V65IN 6.6 GPM Tankless Water Heater
3. Rinnai V65IN 6.6 GPM Tankless Water Heater
This tankless gas water heater is lightweight, ultra compact and is suited for homeowners with two bathrooms.

Best Tankless Water Heater Reviews for 2022

Stiebel Eltron Tankless Water Heater Review

Stiebel Eltron TanklessThe Tempra Plus from Stiebel Eltron Company is the best electric tankless water heater of superior quality.

Most electric tankless heaters cannot handle the high household demands for instant hot water, e.g. a showerhead and a dishwasher simultaneously.

Different from its counterparts, the Tempra Plus can easily support all your extreme hot water demands and supplies instantaneous hot water to four different application points.

Designed to work even in the coldest regions, this electric tankless water heater can offer a maximum of 36kw on 240v.

The digitally controlled temperature allows for easy manipulation and the safety guard feature ensures that the water is never heated above 140F.

Furthermore, thanks to its Advanced Flow Control feature, the heater automatically adjusts the water flow to completely eliminate fluctuation of temperature.

Worth mentioning, the Tempra Plus does not utilize any power at rest.

It installs easily without the need of venting or pressure valves for its operation.

It also works well with all kinds of water ranting from soft, hard, well and city water.

Stiebel Eltron Tempra Plus PROS:
  • The compact size makes for easy installation
  • Works great even in colder regions
  • Setting water temperature is accurate and very simple
  • The unit is super quiet
  • It is able to sustain constant temperature output without fluctuations
Stiebel Eltron Tempra Plus CONS:
  • There is a slight delay before the hot water reaches the tap

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What we think about Stiebel Eltron Tempra Plus:

88 %
95 %
User Rating
90 %
Our Overall Score
91 %


The Stiebel Eltron Tempra Plus is an efficient tankless water heater that serves its purpose very well.

It can supply several application points at the same time and provides a fluctuation-free hot water output.

EcoSmart ECO 27 Tankless Water Heater Review

EcoSmart ECO 27 Tankless Water HeaterIf you want an energy efficient, electric tankless water heater, then a worthy option worth considering is the EcoSmart ECO 27.

The unit comes with a self-modulating heating technology that regulates the energy production, which helps you cut your energy expenses by nearly 50%.

In areas with low water temperatures of less than 40°F, like North America, the EcoSmart ECO 27 can heat roughly three gallons per minute.

At this rate, the system can handle two hot showers simultaneously.

Meanwhile, in warmer regions, the ECO 27 can support six gallons of hot water per minute, thus allowing users to run up to four showers concurrently.

Besides the legible and user friendly digital temperature adjustment, the Eco also features internal jumpers that limit the unit’s heat output.

That means extra safety for the elderly and kids in the house.

To use the ECO 27, you will require a 240v and 27,000 watts electric service.

Additionally, the use of a small, compact design helps save you installation space as it requires less than 15 cubic feet.

EcoSmart ECO PROS:
  • The lifetime warranty assures owners that it is a quality product
  • The self-modulating sensor technology ensures energy efficiency
  • It supports multiple points of use and heats water adequately
  • Stylish and compact design
EcoSmart ECO CONS:
  • Performance may vary based on the water supply temperatures

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What we think about EcoSmart ECO:

87 %
94 %
User Rating
88 %
Our Overall Score
90 %


For most regions, the ECO 27 can produce lots of hot water when you need it.

However, it is advisable to take the temperature of your water supply and your area’s general climate in consideration when deciding whether to buy this unit.

Rinnai V65IN 6.6 GPM Tankless Water Heater Review

Rinnai V65IN 6.6 GPM Tankless Water HeaterThe first gas water heater on this list is the powerful and efficient Rinnai V656IN.

This system is lightweight, ultra compact and is suited for homeowners with two bathrooms.

When placed near the appliances that require hot water, it is very fast and efficient, usually kicking on within seconds of opening the tap.

With error lights and an uncomplicated user interface, the RinnaV656IN indoor tankless water heater is an excellent model for residential use.

It is important to note that adjusting the temperature will change across all fixtures.

This means that if you select a higher temperature when using a Jacuzzi, make sure you lower it afterwards before you turn on the sink to rinse the dishes or clean your hands.

While this unit does require venting, and proper gas, plumbing and electrical maintenance, it is quite reliable and is even certified for installation in mobile homes.

The temperature comes preset at 120 degrees, but you can either reduce the temperature to save energy or increase it to the maximum of 140 degrees.

Rinnai V65IN PROS:
  • Lightweight wall unit that can be installed just about anywhere in a home
  • Constant and adjustable supply of hot water for four fixtures
  • Approved for installation in mobile homes
  • Extensive ten year warranty on the heat exchanger
  • Low power anti-frost protection
Rinnai V65IN CONS:
  • The temperature adjustment cannot adjust individual fixture temperatures.

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What we think about Rinnai V65IN :

80 %
87 %
User Rating
89 %
Our Overall Score
86 %


In conclusion, the medium volume Rinnai V65IN tankless water heater is perfect for small families.

It can comfortably run up to two showers, a faucet and a dishwasher.

Takagi T-KJr2-IN-NG Tankless Water Heater Review

Takagi T KJr2 IN NG Tankless Water HeaterThe Takagi T-KJr2-IN-NG is an outstanding product of renowned Japanese manufacturing company who has built a solid reputation of producing reliable water heaters.

Despite its seemingly small size, you will be amazed that this system has the power and efficiency to run two bathrooms simultaneously with a 6.6 GPM flow rate.

The most distinguishing feature of this Takagi T-KJr2-IN-NG is its thermistors, which are conveniently placed in the inlet and outlet.

These thermistors are essential for monitoring water temperature, making sure that you get a consistent hot water flow rate.

The heater also stays stable and damage proof under operation by automatically shutting itself off once the thermistor chamber temperatures reach the peak limit.

Other safety features include a flame sensor and freeze protection.

Regarding water flow rate, this Takagi water heater provides 6.6GPM at 35 degrees.

Nevertheless, expect the GPM to drop once you start increasing the water temperature.

Takagi PROS:
  • Convenient small size
  • Designed with safety precautions in place
  • Delivers consistent hot water flow rate
  • Easy to use remote panel
Takagi CONS:
  • Not the ideal tankless water heater for a large family

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What we think about Takagi:

84 %
88 %
User Rating
84 %
Our Overall Score
85 %


The Takagi T-KJr2-IN-NG is mostly suited to smaller households with minimal hot water requirements.

With its energy efficient operation and overall dependability, this Takagi tankless water heater is worth checking out.

Eccotemp FVI-12-NG Tankless Water Heater Review

Eccotemp FVI 12 NG Tankless Water HeaterThe Eccotemp FVI-12-NG is an indoor tankless water heater that delivers an average of 4 GPM.

And is mainly geared towards small residences.

Unlike the other heaters featured on this list, this Eccotemp unit is triggered by water pressure of 40 PSI rather than water flow.

Eccotemp has included separate water and gas controls on the front of this water heater for precise adjustments.

There is also a small digital display that shows the current water temperature.

All parts in this system come with a two-year warranty.

The heater runs on natural gas but still requires electricity.

You will need a standard 120V electrical outlet as the unit pulls 10W under operation and 2W when idle.

The electricity is used for driving the digital display and exhaust fan.

Eccotemp PROS:
  • At only 20 pounds, it is lightweight and sleek
  • Electronic ignition
  • Vent kit is included in the package
  • Affordable
Eccotemp CONS:
  • Can only run one bathroom sufficiently
  • No internal anti-freeze protection

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What we think about Eccotemp :

82 %
84 %
User Rating
85 %
Our Overall Score
84 %


The Eccotemp FVI-12-NG is a sleek and compact gas tankless heater with independent water and gas controls.

However, since it only has a 4.8 GPM maximum flow rate, this unit is largely underpowered and will only suit the smallest homes.

Tankless Water Heaters Buying Guide

huge tank water heaterA tankless water heater heats and delivers hot water on demand and is a truly smart investment as it reduces your overall energy consumption.

Rather than storing hot water inside a huge tank, tankless water heaters are only activated to produce hot water when you turn on the shower or faucet.

The water enters the heater and is circulated through a range of electric coils or burners to heat it up before finally exiting the appliance.

There are multiple benefits of switching to a tankless water heater, with the energy savings being a notable one.

If your daily hot water use is an average of 40 gallons, a tankless water heater can significantly reduce your heating costs by over 30%.

The conventional tank-style water heater was notorious for wasting energy in keeping the water hot all day long regardless of whether you needed hot water or not.

Water Heater Flow

The water heater flow is a very important consideration when considering which tankless heater to install.

The average faucet or shower head has 2 gallons per minute (GPM) flow rate while tankless heaters deliver hot water at roughly 2-5 GPM.

It is worth noting that gas-powered units will produce much higher water flow rates as compared to their electric counterparts.

Nevertheless, even the biggest gas-powered model cannot provide adequately hot water for multiple uses, simultaneously in one home.

So, if you don’t want lukewarm water, consider buying a more powerful unit or installing two on-demand tankless heaters in your home.

The other solution is to plan your washing machine and showering time so that they don’t overlap, thus allowing you to enjoy a truly hot shower.

Make sure you choose the right one that best fits your unique needs to have the best experience.

Tankless Water Heater Types:

So you have finally decided to get a tankless heater.

Now you need to decide which type to use, whether it is an electric, gas or portable units.

There are major differences between these different types as explained here below.

1. Electric Tankless Water Heater

With an electric powered tankless water heater, you get 99% energy efficiency.

However, you must confirm that your home has enough electrical power to support the heater.

Here are some of the other benefits of choosing electric tankless heaters:

  • Smaller and more compact design helps to save space
  • No venting necessary as they don’t produce any harmful emissions
  • Cheaper to buy and run silently
  • Electric tankless water heater last longer since there is no combustion needed

2. Gas Tankless Water Heater

The obvious benefit of a gas tankless water heater is that it is much faster than an electric unit.

All gas powered systems require venting to eliminate the harmful gases from your house.

If you go for an outdoor gas model, then you will not have to install any venting system.

Here are other benefits of gas tankless water heaters:

  • Faster and more efficient at heating water
  • Most gas tankless water heaters qualify for tax rebate and other similar incentives
  • Lower monthly energy costs due to higher efficiency

3. Portable Tankless Water Heater

If you want to take your comfortable hot shower along with you for your camping trip, then investing in a portable tankless water heater is the perfect option.

With this kind of heater, you can always access a constant supply of hot water regardless of your location.

Just keep in mind that you will likely have to contend with a low flow rate because of the portability.

Other key benefits are as follows:

  • Small and light in size
  • They allow you to have access to hot water away from home
  • There is no danger of electric shocks

Tankless Water Heater Warranties

One of the benefits of a tankless water heater is the extended warranty period on offer.

The fact that there is no huge tank that will slowly deteriorate after storing water for years means that tankless heaters are more reliable.

That it why warranties on these heaters, even on the critical parts, run up to twenty years.

The conventional tank style hot water tank was quite vulnerable to corrosion, especially from hard water minerals.

In contrast, tankless water heaters do not store water and are less affected by these minerals and can last for more than 20 years.

Additionally, tank style storage heaters end up with a thick coat of minerals on the sides or bottom part.

It reduces the overall heating efficiency and ends up using more energy.

Sizing a Tankless Water Heater

The first consideration when determining the most suitable tankless water heater size is the flow, rather than capacity.

You want a system that will heat the water quickly and also the added benefit of serving multiple points at the same time.

All heaters will have a given efficiency rating and BTU input, which determines is water flow rate (GPM).

Tankless water heaters with higher BTU ratings will deliver higher flow rate or GPM.

For example, it takes 190,000 BTU to provide a hot water flow rate of 5.7 GPM.

Additionally, you should also consider your surrounding climate and the incoming temperature of the water.

Those who live in cold climate areas where the water is quite cold must get more powerful water heaters to be able to produce the heat that is needed to reach the hot temperature.

If the reason you are installing a tankless water heater is to save energy, then you must check the efficiency ratings of the targeted unit.

These ratings indicate how much fuel or electricity is converted for heating the water.

A unit with a higher efficiency rating is capable of heating water quickly and thus saving you money in energy expenses.


Installing a tankless water heater means can offer you numerous benefits like saving energy, space savings, tax rebates and reduced maintenance costs over the unit’s lifespan.

However, ensure you pick the right heater capacity with the ideal flow rate to avoid getting lukewarm water. Even though tankless water heaters have a high initial installation cost, the long term benefits are worth that investment.

1 Comment
  1. Hey, Kenneth Baker. Such a wonderful post!! I am thinking for a long time to buy a water heater. But I am in trouble to think about a question which type of water heater I should buy because there are several types of water heaters, such as electric, gas, undersink etc.

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