5 Best Tankless Water Heaters Reviews (Updated 2023)

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Best Tankless Water Heaters Reviews

Tankless water heaters offer a direct source of hot water, on demand and with no storage tank needed. We’ve researched and reviewed the five top-rated best tankless water heaters, as well as one to avoid.

What are the best tankless water heaters on the market?

✅ 1. Ecosmart ECO 18 Learn More

✅ 2. Bosch Electric Tankless Water Heater Learn More

✅ 3. Rinnai V94EP Learn More

✅ 4. Rinnai RU199iN Learn More

✅ 5. Rheem RTGH-95DVLN Learn More

Review of the 5 Best Tankless Water Heaters, Plus 1 to Avoid

1. Ecosmart ECO 18  

Ecosmart Eco 18 Review

Ecosmart ECO 18 Review: Best Whole House Tankless Water Heater EcoSmart ECO 18 is one of the top-rated and innovative electric and tankless water heaters for residential and commercial use. No more hassles of heavy installations and extensive plumbing work to enjoy a seamless hot water supply.

EcoSmart belongs to the well-known water heater brand Rheem and offers ease-of-use with high durability. The mix of stainless and copper components gives it a longer lifespan—no wonder the manufacturer offers a lifetime warranty on the residential usage of this water heater.

If you are looking for a cost-effective water heating solution EcoSmart ECO 18 can help you save approximately 60 percent on water heating expenses. This is due to its cutting edge self-modulating technology.
While there is no tank, this device works rigorously for a non-stop supply of hot water at a click of a button. No more fiddling about with those manual switches to get the temperatures right. Now you can simply use a digital control panel to set the temperature.

This tankless water heater is an 18 KW tankless electric device that can fit in the tiniest of spaces. Therefore, if you are looking for a townhome, a condo, or an apartment, EcoSmart ECO 18 is the perfect solution for you. You can easily get an excessive amount of water ranging from 1.8 to 4.3 gallons per minute.

Not only will you be using this water heater for personal benefit, but EcoSmart is also a participant in the “Rheem Heart of Comfort Program.” This program donates towards the cause known as “Habitat for Humanity.”

To watch the Ecosmart ECO 18 Review on YouTube, click here.


  • Endless water supply with a correct sized tank for your needs
  • Saves space with sleek and wall-mounted design.
  • Saves time by user-friendly installation and on-demand water supply


  • Some components are not made from metal
  • Only best to use with mineral-free water
  • The manufacturer does not guarantee the elements used.


2. Bosch Electric Tankless Water Heater

Bosch Electric Tankless Water Heater Review

Bosch Electric Tankless Water Heater Review: Best 110 Volt Tankless Water Heater If you are searching for an under the sink tankless water heaters, you may want to consider the Bosch Tronic 3000. This point-of-use water heating solution comes in four compact sizes, and you can easily wall-mount it under your sink, cabinet spaces, etc.

In case you wish to install it in a visible space, the design is sleek and attractive enough to go with any décor. Bosch Tronic 3000 is a durable device that comes with a guarantee of a long lifespan. The best part is that you can use it for residential as well as commercial purposes without breaking a sweat.

You can easily install this tankless water heater in a patio kitchen station, basement wet bar, garage, attic, and even in a boat or RV. This water heater operates at 12 kW and provides a quick and continuous hot water supply.

The experts rate Bosch Tronic 3000’s efficiency to be at 98 percent. In case you are wondering about the water pressure range, it is between 10 to 150 PSI. Moreover, the temperature control is very user-friendly, and the thermostatic control allows you to set the water temperature as per your preference.

The user-friendly interface allows you ease-of-use as you do not have to fiddle around with those wobbly pressure relief valves anymore. The installation is straightforward, and you can put this water heating solution to the test in any setting.

In case you are looking for a hot water supply in your office’s bathrooms, this is a perfect solution. Plus, you will not require any extensive plumbing work to get a hot water supply.

To watch the Bosch Electric Tankless Water Heater Review on YouTube, click here.


  • Reliable and saves space
  • Cost-effective when it comes to energy bills
  • 5-years warranty on heating elements and a 1-year warranty on components


  • Only designed to work of 240 volts
  • May take some time to fill your bathtubs
  • Sensitive buttons that you may have to replace at some point


3. Rinnai V94EP

Rinnai Ru199in Review

Rinnai V94EP Review: Best Outdoor Tankless Water Heater Are you frustrated with having to wait for your water to heat up before you can jump into the shower? Well, you can now put an end to this by installing Rinnai V94EP in your home. This tankless water heater is a perfect device to handle some of the most demanding chores of your household, such a laundry, dishwashing, and showers/baths.

The cutting-edge regulation technology used in Rinnai V94EP allows hot water recirculation through your plumbing pipes. This enables a quick and consistent hot water supply without any delays. The best part is that you get to conserve energy as well as water.

The behemoth water tanks are the thing of the past. Due to its compact design, now you can install the Rinnai V94EP in the tightest of places. If you would like to imagine, this tankless water heater is as big as a small suitcase.

However, do not been fooled by its size because this device can flawlessly fulfill the hot water needs of your entire household. You can use it for both indoor and outdoor purposes. The best part is that you can now control your hot water supply for your smartphone app known as “Control-R 2.0.”

Now you can remotely set a timer or schedule your water heating and even put it in vacation mode. Talking about the heated water flow rate, it varies by the groundwater temperature in your area. However, you can expect it to be at a maximum of 9.4 GPM.

The installation is a relatively simple process and does not require extensive plumbing work.

To watch the Rinnai V94EP Review on YouTube, click here.


  • Cost-effective as it can save you up to 40 percent of energy
  • Eco-friendly as it cuts your CO2 emissions
  • Residential factory warranty with 10 years on heat exchanger, 1-year on labor, and 5-year on parts


  • Confusing instructions for installation
  • A little heavy
  • If you use multiple hot water fixtures at once, the water pressure might drop


4. Rinnai RU199iN

Rinnai Ru199in Review

Rinnai RU199iN Review: Best Indoor Tankless Water Heater Fancy endless hot water supply for the entire household? Well, Rinnai RU199iN is what you must get. This is one of the most efficient tankless water heaters you can buy right now. The best part is that it operates on natural gas and offers a hot water flow at 11 GPM approximately.

You can now set your water heating regulators using a Circ-Logic technology. This means you can now use presets that are usually similar to your hot water usage habits. Rinnai RU199iN uses ThermaCirc360 water heating technology that recirculates heated water through the pipes to ensure a consistent and faster supply of hot water.

Now you do not have to wait for the hot water to travel from your tank to the showerhead. When you switch on the Rinnai RU199iN, you get an instant supply of hot water as per your temperature preference. The best part is that you can now conserve up to 24 16 oz water bottles every time using Rinnai RU199iN tankless water heaters.

You can use this tankless water heater in the tiniest of spaces due to its sleek and innovative design. You can install it within a closet, crawl space, and even in the attic. Do not worry about those huge laundry runs and dishwashing spins; this water heater can handle them with ease.

Even after handling all those chores, Rinnai RU199iN will still have plenty to cater to other hot water needs such as showers and baths. The innovative technology allows you to control your water temperatures remotely over a Wi-Fi connection. Moreover, you can even monitor your tankless water heaters’ health and identify issues before they even occur.

To watch the Rinnai RU199iN Review on YouTube, click here.


  • The average lifespan of 20 years
  • Energy-efficient saving up to 40 percent on the cost
  • Eco-friendly as it limits your CO2 emissions


  • Water temperature may drop slightly due to excessive use
  • The vent is tightly shut, so you may struggle to open it at times
  • The vent fan is too loud for some


5. Rheem RTGH-95DVLN

Rheem RTGH-95DVLN Review

Rheem RTGH-95DVLN Review: Best 120 Volt Tankless Water Heater This tankless water heater saves you an exponential amount of water, especially during its starting phase, and this will also translate into lower utility bills. The Rheem RTGH-95DVLN allows you to activate the built-in water-saving settings during its activation phase. You can save up to 1,100 GPM annually.

Moreover, you can now control your water heater via a mobile app. Turn on that water heater while you are on your way home after a long day at work. You can even get timely maintenance and care alerts on your smartphone.

Another feature of the Rheem RTGH-95DVLN is its “hot start programming” that gives it the ability to minimize your water wastage by remaining in ready-fire mode. This allows this tankless heater to supply continuous hot water to your household.

So when you turn your tap off, the built-in heater still stays on for a few more minutes to ensure enough hot water for the next use. So, no more cold water bursts when you turn on the tap and let the cold water go to waste till you get the hot stream.

Rheem RTGH-95DVLN comes with a self-diagnostic system that helps you or the plumber to install this tankless water heater with ease. The system also offers assistance during service or maintenance.

Rheem RTGH-95DVLN offers you a decent water flow-rate at 9.9 GPM. This model is a natural gas-operated tankless water heater that will not only save you money but also help protect the environment.

Moreover, the overheat film warp in the heater prevents severe temperature rises. This makes it a perfect tankless heater for indoor installations.

To watch the Rheem RTGH-95DVLN Review on YouTube, click here.


  • 12 years warranty on heat exchanger, one year on labor, and five years on parts
  • EcoNet Smart-Home Technology
  • 9.9 GPM water flow-rate


  • Maintenance not listed in the manual
  • Might be a bit challenging to route the condensate drain line
  • Slightly heavy


Avoid – Thermoflow 12KW 

Thermoflow 12kw Review

Thermoflow 12KW Review This is another on-demand tankless water heater; however, it is most suitable for minimal usage. You can enjoy a consistent and seamless hot water supply as long as you do not use multiple fixtures in a bigger household.

The flow rate of Thermoflow 12KW is at 1.8 GPM and offers you heating efficiency of up to 99 percent. The German self-modulating technology regulates temperature pretty well and uses power only when you need the hot water up supply. However, in order to get instant hot water with adequate pressure, you must have a decent and steady inlet temperature or expect flow fluctuations.

You can adjust the temperature via a digital LCD control panel. It allows you to increase or decrease the temperature by 1 degree on each press. The maximum temperature range is between 104 and 150°F.

The design is compact, and you can easily wall-mount it anywhere in your household. This is perfect if you live in a condominium or an apartment, as this conserves space usage. However, you must always verify with the supplier if you are getting the right size for the area you wish to install it in.

That said, Thermoflow is capable of heating up to 2 gallons per minute and offers you a maximum flow rate of 2.8 GPM. The Flex 12 technology used in this water heater is suitable for areas where the temperature may fall to 57°F.
You will also get a backlit LCD panel using touch screen technology. While it offers the convenience of use, it may fall short when it comes to dealing with a household with heavy hot water needs.

To watch the Thermoflow 12KW Review on YouTube, click here.


  • Saves energy
  • Stylish and compact design
  • Wall mountable


  • Only suitable for small apartments
  • Hard to get through to the customer support
  • Pressure may drop if used excessively


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2022 Buyers Guide to the Best Tankless Water Heater:

There are a ton of things to consider when you’re buying a new tankless water heater. Like many other devices made for the home, these items can require installation from a professor or willing handiperson. With the territory comes some technical jargon, but we’ve simplified it and found three aspects you must consider before buying a tankless water heater, including how much hot water you need, your climate, budget, and how much installation will cost.

3 Main Points to Consider

  • Energy Source: There are 2 options for energy sources, either gas or electric. Many people that are switching from a conventional water heating tank to a tankless water heater are looking to trim down their utility bills. Although with a tankless you’ll see an improvement on your utility bills, either way, electric models aren’t as efficient as natural gas options. Both options have their benefits and downfalls. But, the drawbacks for some could be benefits for others. For instance, gas is cheaper than electric, however, in some places gas is easier to manage and can withstand cooler climates better. However, a smaller household could do better with an electric water heater because they don’t need the power behind a gas tankless water heater. Not to mention that gas water heaters are more expensive than an electric option.
  • Hot Water Demand: Tankless water heaters have an advantage over traditional water heaters because you can choose which unit works best for your water demands. Most houses have traditional tank water heaters that allow for a much higher demand than the household needs. Water heaters work differently than the traditional tank heaters because they heat water as you need it instead of holding tons of hot water. These water heaters acknowledge the hot water demand through flowrates. For a large water demand, you should aim for a higher flow rate which measures in gallons per minute. The more gallons per minute the tankless water heater can handle, the better it is for large households. However, if you are living alone or have a small house, you don’t need all that power and will probably never use it. To figure out what the best range of GPM is for you and your household, start by counting the showers. Each shower uses between 2 and 3 GPM for adequate water pressure. Add each shower’s needs and then add 1 gpm per appliance you plan on running at the same time. So, if you have 1 shower, a sink, dishwasher, and clothes washer that you want to run all at the same time you need at least 5GPM.
  • Climate: A tankless water heater has to battle their environment to sustain how water. So, the lower the outside temperature, the lower the flow rate will be. Throughout the northern area, the climates have lower inlet temperatures which mean that your water heater must work harder. Higher flow rates are the solution to in climate regions. They offer more effective heating during cold weather. Until recently many homeowners weren’t able to have tankless water heaters because of the cold months. Always round up when you’re trying to figure out which flow rate works best for you. There’s always a margin of error, and you can’t be certain that last years temperatures are an accurate prediction of the weather in the years to come. However, people in warmer climates have a little more wiggle room. Throughout the Southern region of the United States, many homeowners disconnect their water heater because it’s not necessary.

What is the difference between a traditional vs tankless water heater?

The difference comes down to how the water heaters operate. A traditional water heater holds gallons of water which at a certain temperature. Tankless water heaters use its components to heat water as you need it. When you turn on a faucet, it’s system kicks on and starts heating.

In the long run, the big difference is in price. A tankless water heater is usually more expensive at first but will save you money in utilities over the years. You can easily increase efficiency by about 25% when you consider the average water usage in a small to medium family home.

Tankless water heaters are increasing in popularity because of their longevity. Because a traditional water heater holds somewhere between 30 and 50 gallons of water for an unknown amount of time, their inner components experience a lot more water exposure.

However tankless water heaters provide hot water on-demand, so their components are usually dry.

The fact of the tank is the biggest difference between the 2 options, but this difference spurs some other benefits and downfalls. Many people enjoy having the extra bit of space in their garage from a tankless water heater.

However, many people can’t afford to buy the tankless water heaters and pay for the installation. If it comes down to budget, you’ll need to closely evaluate not only the price difference from the initial cost but also for any necessary retrofitting.

Final Thoughts on Buying a Tankless Water Heater

A water heater is an effective solution to get instant hot water with a click of a button. You can now use tankless water heaters that can help you save time, energy, and space while offering a continuous and faster supply of hot water.

However, you must research what kind of inlet water temperature you get in your household and what your maximum usage is. Knowing both of these factors will allow you to pick the tankless water heater that suits your demand.

You must always make sure to purchase the right water heater to avoid running out of supply. Do consider your budget and buy the best available option in your range. Most importantly, to avoid any hazards, always seek professional assistance for the installation

If you live in the United States and wonder which of the states rank the highest in demand for tankless water heater, here is the list to help you out. According to Google Trends, the top 5 US states with the most significant demand for water heaters are Wyoming, South Carolina, Louisiana, Arkansas, and New Mexico.

That said, the tankless water heaters mentioned in this post are some of the best you can buy in 2022. So have your pick to enjoy an endless supply of hot water for your entire family.

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