Best Tankless Water Heaters


A tankless water heater is a type of water heater that does not require a tank to create hot water. These water heaters are a great way to save space and money when having your water heated. They are smaller than storage tank heaters and run more efficiently. When you’re in the market for the best tankless water heater, you need to do ensure you buy the right products and you need to know how to install them. Below are our recommendations for tankless water heaters that are worth getting.

Best Tankless Water Heaters Reviewed

Rinnai V75iP Tankless Hot Water Heater


  • 7.5 GPM flow rate
  • Mobile app for remote features
  • 10-year warranty on heat exchanger
  • Works for your entire home


  • Indoor use only
  • More expensive option

The Rinnai V75iP tankless water heater might be on the higher end of the price scale, but it pushes out enough water to use for your entire home. Its propane powered, but you’ll still need to plug the tank into a 120-Volt outlet to use it.

With a 7.5 gallon per minute flow rate, there’s plenty of hot water to go around with this tankless water heater. Even better for those trying to minimize their energy bill, the Rinnai V75iP Tankless water heater comes with a mobile app that allows you to set your heater up from wherever you are.

Want to set your water heater on vacation mode? Have it quick on right before your morning shower? Check and check. Finally, it comes with a 10-year warranty on the heat exchanger, so it’s one less thing for you to worry about.

Takagi T-H3-DV-N Natural Gas Tankless Water Heater


  • Built-in surge, freeze and overheat protection
  • 10 GPM flow rate
  • Highly efficient copper alloy heat exchanger
  • Energy Star certified


  • Most expensive option

If you’re looking for a top-of-the-line gas-powered tankless water heater for your home, look no further. The Takagi water heater comes with a litany of safety features, like surge protection, freeze protection, and overheating protection.

With a 10 gallon per minute flow rate, this is the perfect tankless water heater for residential and small commercial settings. Whether you’re trying to find room for a water heater at your beauty salon or just want to enjoy a long hot shower, this is a great option.

It utilizes a copper alloy heat exchanger, which is 25 more times efficient than stainless steel. This gives you more hot water in less time. It also adds to its Energy Star certification, making it one of the most efficient tankless water heaters available.

The only con to the Takagi T-H3-DV-N tankless water heater? The top of the line water heater comes with a top-of-the-line price tag. But for what you’re getting, it’s not a bad price.

NPE-210S Tankless Water Heater


  • Energy Star certified
  • Runs off both propane and natural gas
  • Built-in surge, high water temp, high exhaust temp, and APS protection


  • 5.2 GPM flow rate
  • Heavier design at 75 pounds

The NPE-210S tankless water heater is one of the more versatile options on the market. It runs off both propane and natural gas, so no matter your setup, this tankless water heater can handle it. Despite its versatility, it’s still Energy Star certified, making it a cinch to lower your monthly energy bills.

The NPE-210S water heater comes equipped with a wide range of safety features, including APS, surge, high water temperature, and exhaust high-temperature protection.

It is quite heavy for a tankless water heater at 75 pounds, although this is still tiny compared to the traditional water heater. It also only puts out 5.2 gallons per minute, which is fine for smaller residential applications.

However, if you’re going to be drawing large amounts of water demand or be running your tankless water heater in colder conditions, you might find this tankless water heater struggling to keep up.

Ecosmart ECO 18 Electric Tankless Water Heater


  • Very affordable option
  • Lifetime warranty for residential use
  • Control water temperature in 1-degree intervals


  • Made in China
  • Between 1.8 and 4.3 GPM flowrate

If you’re looking to convert your home to a tankless water heater and don’t want to break the bank on the heater, this is a phenomenal option. The ECO 18 is a Chinese brand, but it does come with a lifetime warranty for all residential applications.

Even better, you can control your water temperature in 1-degree intervals, giving you the ultimate control of how hot your water is. However, the ECO 18 option can only put out between 1.8 and 4.3 gallons per minute, depending on the water’s inlet temperature.

So, if you’re planning on heating water across multiple areas simultaneously, you’ll want to install a tankless water heater for each application. But for the price of the Ecosmart ECO 18, you can afford to do this!

Bosch Electric Mini-Tank Water Heater


  • Has 2.5-gallon tank for instant hot water
  • Easy install
  • Incredibly light at 15.5 pounds
  • Perfect for small applications like sinks and boats


  • Not truly tankless
  • Most affordable option that we reviewed
  • 6.8 GPH recovery rate

Technically the Bosch electric mini-tank water heater isn’t a tankless water heater. But that’s both a blessing and a curse. This mini-tank heater can instantly provide hot water, but it can only produce up to 6.8 gallons per hour and only has a 2.5-gallon tank.

It’s why this mini-tank water heater is perfect for an under the sink application. You won’t be using a ton of water at one time there, and it’ll be hot instantly for you. It’s incredibly light at 15.5 pounds so that you can mount it directly into the cabinet under the sink.

It’s insanely easy to install. All you need to do is plug it in and hook up your water line – no conversion kits are required. Even better, it’s an insanely cheap option. In fact, it was the most affordable option that we reviewed here.

If you don’t need a ton of hot water or you’re only looking to heat water in one area, you don’t need a full tankless water heater. All you need is the Bosch electric mini-tank water heater.

What are the Benefits of a Tankless Water Heater?

There’s a reason that people say tankless water heaters are the way of the future. They offer a wide array of benefits over traditional water heaters – for both you and the environment!

Endless Hot Water

It’s the single most significant benefit that you’ll notice from a tankless water heater. A traditional water heater heats your water and stores it for you in a tank until you need it. While this gives you instant hot water, it also creates the possibility that you can run out of hot water.

Tankless water heaters heat the water as it passes through the heat exchanger, providing you instant hot water that never runs out. The only concern is that each tankless water heater can only heat so much hot water at a time, depending on the water flow rate of the heater. So, if your demand outpaces what the tankless water heater can produce, you’ll overload the system and end up with no hot water.  

Space Savings

Traditional water heaters are enormous plumbing appliances. They have to be, or else you’ll run out of hot water exceptionally quickly. But since tankless water heaters don’t need to store any hot water, their sizes are significantly reduced. In fact, they can often be installed directly in your home – as long as you correctly route the outlet hoses.

A tankless water heater can free up tons of space in your garage or basement. Even the most massive tankless water heaters are half the size of an average traditional water heater, and some of them are closer to 1/10th the size.

Energy Savings

Keeping large amounts of water warm throughout the day eats up a ton of energy. But that’s precisely how traditional water heaters work – this isn’t good for the environment or your wallet. Tankless water heaters are different since they don’t need to keep large amounts of water warm around the clock. They use far less energy. This lowers your utility costs month after month.

What are the Downsides of a Tankless Water Heater?

While there are many benefits to tankless water heaters, they aren’t all rainbows and butterflies. They have disadvantages and depending on your setup, they might not be worth the hassle.

Can Take A While to Heat Up

If you’re turning your tankless water heater on and off to save energy, it takes time for everything to start up. While some options, like the Rinnai V75iP tankless water heater, let you set these features up through a timer, other options require you to turn it on and off manually.

Even when the tankless water heater is on, the heat exchanger doesn’t kick on until it detects water flow. This means it might take a few seconds for the water to warm up. While there are ways to get around this, most people wait a few seconds.

High Maintenance Costs

While it’s true that you’ll save on your monthly energy bills, you’ll need to put that money back to service your tankless water heater. Tankless water heaters aren’t as reliable as the traditional ones.

This makes it especially important to find a tankless water heater with a good warranty from a reliable company that will honor it. Even still, your tankless water heater will require routine maintenance that the warranty won’t cover.

High Upfront Costs

If you think you can buy a tankless water heater and chuck your traditional water heater without any more work, think again. Tankless water heaters require full conversion kits, and this isn’t cheap. You’ll generally have to run new lines for the exhaust, and you’ll need to install lines for either the natural gas or propane.

If your home doesn’t use natural gas, propane is generally the cheaper option, but it limits the kinds of tankless water heaters you can get. Most homeowners will never see any savings from a tankless water heater between the higher upfront costs and repeated maintenance costs. While they don’t cost more, they don’t cost any less either.

Scale is a Problem

If you’ve ever been responsible for a property with a tankless water heater, then you know that scale buildup is a common occurrence. It’s easily avoidable if you repeatedly and consistently flush the system, but this takes time, and it’s just one more chore to add to the list.

Endless Hot Water – Not Endless Throughput

While it’s true that a tankless water heater can provide endless hot water, it can only heat up so much at a time. Your inlet water temperature will cause the amount of hot water your tankless water heater can push out per minute. If you’re living in a colder climate, you’ll need a more powerful tankless water heater to meet your needs.

Can you Run Out of Hot Water With a Tankless Water Heater?

No, you will not run out of hot water with a tankless water heater. As long as you have water being supplied to the water heater and the water heater is working properly, you will have hot water. Keep in mind there is a limit to how much water can be heated at a given time, so be sure to check the flow rate limit of your tankless water heater.

Are Tankless Water Heaters Gas or Electric?

Tankless water heaters can be either gas or electric. Depending on your preference, one may be a better option for your home than the other.

Where Do You Install Tankless Water Heaters?

Depending on the application and where you need to use the water heater, your tankless heater can virtually go anywhere as long as there’s enough airflow.

Can My Tankless Water Heater Freeze? 

While many tankless water heaters have protection to withstand temperatures, again it depends on where you install it. If you live in colder climates, adding extra insulation is always a good idea. Read your installation manual for more tips.

Final Verdict

While even the best tankless water heater isn’t perfect, they can be a more environmentally friendly solution that lowers your monthly energy bills. If your home doesn’t have natural gas, you’ll want to invest in a propane-powered tankless water heater, but you’ll still need a power outlet for either option.

So, is a tankless water heater right for you? It depends on what you’re looking for. But if you want endless hot water and to ditch your large, clunky water heater, a tankless water heater might be precisely what you’ve been looking for.

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