6 Best Tankless Water Heaters

6 Best Tankless Water Heaters


After 9 hours of research evaluating 20 products, we picked EcoSmart ECO 27 Electric Tankless Water Heater as our top choice.

Hot water is a MUST for a happy home! Without it, you can't wash dishes, wash your hands properly, or take a shower or bath. We're all willing to pay a higher gas bill if it means we get plenty of hot water every day.

But what if there's a cheaper way?

Even the best tankless water heaters are significantly cheaper than regular water heaters. The fact that they ONLY heat up water when you need them means you save a lot on your gas bill every year—between $44 and $108, depending on the type of water heater you have.

Sure, tankless water heaters aren't perfect—they're pricier than regular water heaters and can be inconsistent with hot water output—but they're the eco-friendly, energy-saving option to consider!

Want to know the best part?

We've gone through thousands of the best tankless water heater reviews and evaluated all the products on the market to determine the best tankless water heater for you. Below, you'll find a list of options that will suit all your hot water needs.

Our editors independently research, test, and recommmend the best products; you can learn more about our review process here. We may receive commissions on purchases made from our chosen links.

6 Best Tankless Water Heaters

  • 6. Marey Gas 10L Tankless Water Heater
  • 5. Rheem RTGH-95DVLN
  • 4. Rinnai RL75iN Natural Gas Tankless Water Heater
  • 3. Takagi T-H3-DV-N Tankless Water Heater
  • 2. Stiebel Eltron Tempra Plus 24 kW
  • 1. EcoSmart ECO 27 Electric Tankless Water Heater

Best Budget Tankless Water Heater


Marey Gas 10L Tankless Water Heater

Best Budget Tankless Water Heater: Marey Gas 10L Tankless Water Heater
111 Bought
76 % Editor Score
80 % User Score

Why People Love it

  • A great choice to reduce energy costs during the summer
  • Compact and affordable
  • Great for small households

Low-priced model, low operating costs, eco-conscious, battery operation, only switches on when hot water is required, small carbon footprint, and compact model.

Low water capacity, difficult installation, and slow heating.

Hot Water Output: The heater can deliver up to 3.1 gallons of hot water per minute, which means it's enough for two showers or sinks at once. However, prepare for a long heating time—you'll have to wait at least a minute for the hot water to come out of the showerhead.

Reliability: The heater is battery-operated, so all of the controls will be powered by 2 D-Cell batteries. The heater will only switch onto gas when you need hot water, meaning it will use far less electricity and gas than other models on our list. If your goal is to reduce your carbon footprint and you don't need a lot of hot water, it's your best choice.

Sadly, the heat efficiency is fairly low: just 54 to 87%.

Features: The gas and water controls are easy to adjust, and you'll find it's one of the most user-friendly heaters once it's installed. However, installing it can be quite tricky and will require a professional.

Price: Given its incredibly low price tag—around $220, depending on LP or natural gas consumption—it's a model we had to include on our list. It may not be the most reliable or efficient, but it's great for saving money on your energy use and the initial appliance purchase.

Most Reliable Tankless Water Heater



Most Reliable Tankless Water Heater: Rheem RTGH-95DVLN
140 Bought
76 % Editor Score
82 % User Score

Why People Love it

  • A highly reliable water heater with consistent hot water output
  • High flow rate: 9.5 GPM
  • Energy efficient and user-friendly

Easy to operate, electronic controls, 94% thermal efficiency, high water output, up to 199,000 BTUs, self-diagnostic system, remote control included, and easy to install anywhere.

Pricey and complicated venting systems required.

Hot Water Output: The hot water heater delivers a stunning 9.5 GPM, almost on par with the highest-output Takagi model. It's also surprisingly energy efficient, with a 94% thermal efficiency, meaning there is very little heat loss while the appliance is heating up your water. Thanks to the high flow, you have enough hot water for 4 or 5 showers, sinks, and faucets.

Reliability: Unlike some of the other models on our list, this heater doesn't suffer from consistency problems. Thanks to its high BTUs (199,000), it heats up water very quickly, providing a steady supply of hot water no matter how long you shower.

The operation of the heater itself is also beautifully simple, and the installation won't require a professional. You can DIY it all, thanks to Rheem's Low Nox system. Plus, with the remote control, it's easy to adjust the temperature and settings without having to step foot in your boiler room.

Note: This heater requires a venting system, one that is surprisingly complex. You may want to consult a plumber to ensure it's done correctly.

Features: The intelligent electronic controls are designed to make it easy for you to "set it and forget it". All you have to do is set the temperature to your desired heat output, and the digital controls will keep it at that setting until you change it in person or via the remote. The controls also enhance safety, reducing the risk of overheating, leaking, or frost build-up in winter.

Price: At $1,200, this is one of the priciest tankless water heaters on our list. However, given its reliability and high water output, it's a decent option to consider.

Best Tankless Water Heaters for Large Families


Rinnai RL75iN Natural Gas Tankless Water Heater

Best Tankless Water Heaters for Large Families: Rinnai RL75iN Natural Gas Tankless Water Heater
126 Bought
82 % Editor Score
86 % User Score

Why People Love it

  • Highly energy-efficient hot water heater
  • Delivers consistently hot water for large families
  • Compact, can be converted to LP and natural gas

Consistent hot water output, 82% thermal efficiency, commercial and residential settings, digital controller included, good flow rate, LP and natural gas-powered, sealed combustion system, and safety elements are built in for your protection.

Slight hot water output delay and installation is tricky.

Hot Water Output: This gas-powered water heater is able to deliver as much as 7.5 gallons per minute—an output almost on par with the Takagi heater. However, though it doesn't quite match the Takagi's 10 GPM output, it delivers much more reliable and consistent heating.

You get a short delay (30 second) before the hot water hits, but once it's on, you'll find it stays consistently hot throughout your shower. The high output means you can run two or three showers and sinks at once without overtaxing the heating system.

Reliability: The heater is designed to be highly reliable, with heating elements that can produce anywhere from 10,000 to 180,000 BTUs. The commercial and residential settings will allow you to adjust the heater according to its location and use. With an 82% thermal efficiency, it's a highly reliable heater that will help you to conserve energy—both LP and natural gas, according to your preferences.

The heater is surprisingly compact—just 14 x 23 x 9.3 inches—so it can be installed in any home or apartment.

Features: The digital controls allow you to raise or lower the temperature easily, and you can set it anywhere between 98 and 160 F.

The system is a bit tricky to install, so it's recommended you use a professional electrician or plumber to do the work for you. However, once it's set up, you'll have no trouble using it. The built-in safety controls will prevent the heater from overheating, protect it from frost, and even reduce the risk of an electric power surge damaging the heater.

Price: At close to $940, this is on the pricier side of the scale, but definitely worth owning if you have a large family (5+ members) that uses a lot of hot water. Thanks to the consistency of the hot water output, you'll never have to worry about cold showers again.

Highest Output Tankless Water Heater


Takagi T-H3-DV-N Tankless Water Heater

Highest Output Tankless Water Heater: Takagi T-H3-DV-N Tankless Water Heater
132 Bought
86 % Editor Score
89 % User Score

Why People Love it

  • Enough hot water to supply a large-family home
  • Self-installation surprisingly simple; get it up and running in no time
  • Steady hot water output while still offering energy-efficiency

10 gallons per minute, excellent cold weather performance, digital remote, easy to use controls, no overheating, auto shut-off, frost guard, larger connections, and computerized safety features.

Pricier than most and inconsistent heating.

Hot Water Output: While most reviewers agree that the water heater can produce anywhere between 6 and 8 gallons of hot water per minute, some have insisted that it gets up to 10 GPM. Compared to the 2-5 GPM common with most hot water heaters, this one performs far better than the rest!

Though it's a gas heater (and thus costlier to run than an electric heater), it's still very energy-efficient and delivers hot water with minimal heat loss.

Reliability: The hot water heater is highly reliable, with a user-friendly installation and operation that will make it a dream to run in your home. It's bigger and heavier than some of the other tankless water heaters on our list, but that actually helps to facilitate the higher water output.

The water connections to and from the heater are larger than average, allowing for a higher flow of water into and out of the heater. The heating can be inconsistent, especially in cold climates, but you'll find it's more than enough for any 5+ family home.

Features: The digital controls make it easy for you to adjust your heat settings as desired, and there's even a remote control for maximum convenience. The heater comes with a built-in lighting mechanism, so no need to futz with a pilot light.

The auto shut-off feature will prevent the heater from overheating, and the safety features are all computerized. There are even altitude settings to adjust your heater to higher altitudes and colder climates.

Price: At $1,225, this is the priciest tankless water heater on our list. It delivers reliability and excellent performance, but it's close to three times as expensive as our top-rated model.

Most User-Friendly Tankless Water Heater


Stiebel Eltron Tempra Plus 24 kW

Most User-Friendly Tankless Water Heater: Stiebel Eltron Tempra Plus 24 kW
124 Bought
91 % Editor Score
93 % User Score

Why People Love it

  • A highly reliable, easy-to-operate water heater
  • Delivers precise temperature ranges, which are easily adjusted
  • Reduced energy expenditure, yet consistent water output

Incredibly compact, very user-friendly digital controls, no venting required, reliable, water flow control, electric-powered, maintains steady temperature, seismic-proof construction, easy to install, energy-efficient, minimal water pressure loss, and heavy-duty electronic components.

Requires two 60-amp circuits, and the water connection must be detachable for periodic filter cleaning.

Hot Water Output: This hot water heater can deliver anywhere from 2.6 GPM to 5 GPM, depending on how cold the climate and how hot you want your water. With its 24 kW heating system, it delivers a surprisingly steady stream of water. It can handle up to 150 psi, but the water pressure will be minimally affected by the heating process.

With heating temperatures between 80 and 140 F, it will deliver all the hot water you need for your sinks, dishwashers, and showers!

(Note: The output is insufficient for high-flow fixtures, but perfect for low-flow faucets and showerheads.)

Reliability: This is one of the most reliable tankless hot water heaters, though it requires heavy-duty electronic components. It runs off two 60-amp circuits, and may require an electrician or plumber to install it properly. Once it's installed, however, you'll find it can handle a lot of regular use—it's even built to be resistant to earthquake damage!

It's also one of the most energy-efficient water heaters on our list, with a 240-volt, 1,440 watt operation. If you have limited space, this compact water heater—21.5 x 19.5 x 8.8 inches—is exactly what you need.

Features: The heater comes with built-in auto-modulation controls, which will regulate the hot water output automatically. The Advanced Temperature Controls will keep water temperature consistent as you shower, and you'll find the digital heating display makes it easy to set and adjust the temperature to save energy or increase the heat of the water. It runs totally silently, and there is no need for venting!

Price: At $700, this is getting toward the pricier side of the scale, but absolutely worth it if you want reliability and user-friendly operation. Plus, with the 7-year leakage warranty and 3-year parts warranty, you know it's a quality appliance!

Best Tankless Water Heater Overall


EcoSmart ECO 27 Electric Tankless Water Heater

Best Tankless Water Heater Overall: EcoSmart ECO 27 Electric Tankless Water Heater
203 Bought
96 % Editor Score
96 % User Score

Why People Love it

  • An energy-efficient, highly reliable hot water heater
  • 1-degree temperature increments for maximum control
  • Affordable price tag, yet durable and well-built appliance

High energy efficiency, heats water on demand, lifetime parts warranty, compact heater, ideal for smaller families, durable components, easy to mount, excels in cold climates, 3-6 gallons per minute output, and the temparature is very easy to control.

Flow rate is not quite seamless and not suited for larger families.

Hot Water Output: This tankless water heater has the ability to heat up between 3 and 6 gallons per minute—cold weather reduces the water output. If the weather is very cold (below 32 F), the hot water output can be a bit unreliable, and the temperature may be a little inconsistent. However, for the average home, it's more than sufficient to heat up water for two showers at once.

Be warned: this is NOT the heater for a large family. (See the Takagi for that.) If you have a family of 4 or fewer, this water heater can generate enough output to deliver all the hot water you need.

Reliability: Reliability is one of this heater's main selling points. Not only are the copper and steel components highly durable (even in cold/freezing weather), but the heater itself is incredibly user-friendly. DIY installation is a lot simpler than you'd expect, and once you get it up and running, it will reliably heat water for years to come.

The heater comes with a lifetime warranty, guaranteeing its reliability. (Note: Warranty may not cover a heater DIY installed.)

The fact that it's an electric heater means you'll drastically cut costs—electric heating is cheaper than gas-heated water.

Features: The Digital Display Panel makes it easy for users to adjust the heater's settings as desired. The thermostat is adjustable in 1-degree increments, allowing you total control over how hot you want the water to be. To cut energy costs, turn down the heater just a few degrees—you won't notice the difference when you shower, but definitely when it comes time to pay the electric bill!

Don't have a lot of space in your apartment or house for a hot water heater? This little appliance—just 17" x 17" x 3.6"—will fit anywhere in your home.

Price: At $450, this is one of the best-priced hot water heaters on the market. Add to that the fact that you're going to save big-time on your monthly electric bill, and you have an excellent reason to buy this tankless water heater today!

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Fitness has come hard for Andy; he's had to work for it. But, his trials have led him to becoming a martial artist, a NFPT-certified fitness trainer, and a man passionate about exercise and healthy living. That’s why he’s our resident fitness expert.

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