Best Tankless Water Heaters (2022)
 Ecosmart ECO 18 |  Stiebel Tempra | | |  Rinnai V65iP | | |  Furrion 2.4 |
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Best electric tankless heater | Runner up electric heater | Best gas tankless heaterWhy we like: | Runner up natural gas heaterWhy we like: | Best propane tankless heaterWhy we like: | Runner up propane heaterWhy we like: | Best RV tankless heaterWhy we like: | Runner up heater for RVsWhy we like: |
Tankless water heaters are the modern solution to home water heating. By sensing when you turn on a faucet, these devices do away with bulky water tanks and heat water on-demand with efficient copper heating elements.
This means the best tankless heaters provide continuous hot water while saving large amounts of energy. Tankless owners can expect 30-40% utility bill reductions, simply by no longer heating water that isn’t needed.
Whether you choose an electric, natural gas, or propane fuelled system, you can expect a smaller, quieter heater that will last much longer than a traditional boiler. According to the US Department of Energy, tankless heaters have an average lifespan of 2 decades, thanks to simpler mechanisms and no contamination from sitting water.
Each heater model comes with different pros and cons, and the type of fuel you use should depend on multiple local factors—so which tankless heater should you choose?
What’s on this page?
We’ve put together the results of each of our tankless water heater reviews. Scroll to browse the top products in each category or check out the winners here:
Best electric tankless water heater
Reviews: 4.6 out of 5
Power: 36 kW/140 F
GPM: Up to 7.5 GPM
Efficiency: 99%
Use: Large homes
The Tempra is the best-reviewed electric water heater on the internet—we like it too! It provides fast, consistent heating thanks to 7.5 GPM and renowned self-modulating technology, and contains a sensitive flow reader that picks up small adjustments at the faucet. Read our full review.
- Reviews: 4.5 out of 5
Power: 18 kW/140 F
GPM: Up to 4.3 GPM
Efficiency: 99.8%
Use: Mid-size homes
The Ecosmart ECO 18 is a popular choice for average-size homes and our Best Buy pick in this category. It’s a small unit with a winning balance of features and retail price—and it runs at an energy factor of 99.8%, making the ECO 18 as efficient as water heaters get. Here’s our review.
Reviews: 4.5 out of 5
Power: 18 kW/140 F
GPM: Up to 4.4 GPM
Efficiency: 99.8%
Use: Mid-size homes
Rheem is the most recognizable US name in tankless heaters, with this RTEX-18 model being the brand’s most popular electric tankless option. Its self-modulating brass-topped heating elements can outlast similar competitors and offer amazing heating efficiency. Read the review.
For most homes, tankless electric systems are the best available type of water heater. Compared to tank boilers and gas options, electric models are more efficient, longer-lasting, and less expensive to purchase and install. Unless you live in a cold climate, have fragile wiring, or higher than average water needs, we recommend going electric.
Best gas tankless water heater
- Reviews: 4.6 out of 5
Capacity: 180,000 BTUs
GPM: Up to 7.5 GPM
Efficiency: 82%
Type: Mid-size homes
The Rinnai RL75I is our Best Buy pick for 2-3 bathroom homes. It has a large BTU capacity and high GPM flow rate, meaning you shouldn’t experience any drop in flow rate when multiple outlets are running. At just 49 decibels, it’s also one of the quietest gas heaters out there.
Reviews: 4.3 out of 5
Capacity: 150,000 BTUs
GPM: Up to 5.2 GPM
Efficiency: 92%
Use: Outdoor install
Mounting a gas heater outdoors means cheaper install costs and no need for venting. We think the Camplux Pro is a great option for outdoor installation, thanks to its water-resistant, electrical overload, and fan failure protection. It’s also able to resist grade 8 wind speeds!
Reviews: 4.3 out of 5
Capacity: 199,000 BTUs
GPM: Up to 10 GPM
Efficiency: 93%
Use: Large homes
Even though it’s one of the most powerful heaters on this page, the Takagi T-H3 boasts an high energy factor of 93%. It achieves this thanks to condensing technology, which captures residual heat from the exhaust and redeploys it to preheat incoming water.
While gas tankless water heaters are often more expensive than electric models, that upfront investment is offset over time, as most areas enjoy lower natural gas prices than electricity. Gas heaters are also more powerful, able to heat large homes and those in colder parts of the country. Choose a gas tankless heater if you have significant water heating needs.
Best propane tankless water heater
Reviews: 4.6 out of 5
Capacity: 150,000 BTUs
GPM: Up to 6.5 GPM
Efficiency: 82%
Use: Mid-size homes
For homes with 1-2 bathrooms that run on propane, the Rinnai V65iP is our Best Buy pick. Designed for indoor installation with an efficient BTU to flow rate ratio, this model is the most popular heater in the brand’s V-series line.
- Reviews: 4.6 out of 5
Capacity: 68,000 BTUs
GPM: Up to 2.6 GPM
Efficiency: 88.5%
Use: RVs / Point-of-use
The Camplux 10L Outdoor might just be our favorite road trip buddy. An awesome way to enjoy hot water in RVs, camps, or cabins, it produces 2.64 GPM through an integrated shower attachment.
Reviews: 4.5 out of 5
Capacity: 199,000 BTUs
GPM: Up to 11 GPM
Efficiency: 96%
Use: Large homes
While it’s not much bigger than a roller suitcase, the Rinnai RUR199iP is the most powerful in the Sensei SE+ line and has the highest GPM on this page. It’s capable of running large homes and many appliances at the same time.
When you’re buying fuel by the gallon, having an energy-efficient heater becomes a priority. Propane tankless water heaters offer a simple way to manage your gas usage, whether you’re at the cabin, on the road, or own a home with a permanent propane tank. We recommend propane tankless heaters for rural homes, recreational vehicles, and off-grid use.
Best RV tankless water heater
Reviews: 4.5 out of 5
Capacity: 60,000 BTUs
GPM: Up to 2.4 GPM
Efficiency: 81%
Type: Propane
While it only runs a single appliance, the Furrion 2.4 GPM seriously improves your RV experience, with a bunch of useful features. It contains VibrationSmart technology to help withstand uneven terrain and will operate down to 32 degrees.
Reviews: 4.5 out of 5
Power: 1.4 kW/145 F
GPH: 6.8 GPH
Efficiency: 98%
Type: Electric
The Bosch Tronic 3000 has a small 4-gallon tank, but its electric power provides instant water in most situations. The tank refills in under an hour, making it a perfect point-of-use device for RVs, boats, or guest houses.
- Reviews: 4.6 out of 5
Capacity: 68,000 BTUs
GPM: Up to 2.6 GPM
Efficiency: 88.5%
Type: Propane
Lightweight and propane-powered, the Camplux 10L Outdoor is the most portable of these 3 heaters. Mount it to your vehicle or keep it in the back of your truck for setting up a fully functioning camp kitchen or bathroom.
There’s something luxurious about access to a warm shower or hot water for cleaning while out in your RV, Boat, or at a permanent camp. These heaters are made to be durable, portable, and deploy propane, natural gas, or electricity on-demand to maximize fuel efficiency.
Why choose a tankless water heater?
People are transitioning away from tank heaters for several reasons. Tankless heaters are a newer technology, greener, and less expensive. They also produce more hot water at a reduced cost.
Here’s why you should trade in your traditional tank boiler and switch to a tankless water heater.
Goodbye to noisy, bulky water tanks
Traditional “boiler” style heaters were not designed with efficiency in mind. They take up an inconvenient amount of space in your home, requiring considerable room in a basement or large cupboard. They’re also often scalding-hot to the touch, meaning they can be a danger to young children if not stored out of sight.
Bulky, noisy, and leaky? No thanks.
In addition to their size, old-school heaters don’t keep tabs on how much hot water you actually use; instead pre-filing their tanks with hot water, which then is depleted throughout the day. This causes three common issues:
First, if you run through the whole tank, you can be left without hot water while the system slowly refills.
Second, if you regularly use less hot water than the size of your heater tank, you’re continually paying to heat unneeded water.
And third, leaving warm water sitting inside an aging tank can be a recipe for potential leaks, flooding, and contamination by bacteria.
In summary, we don’t recommend tank heaters because…
- Many gas-fired tank heaters operate at half the efficiency of tankless heaters. Today’s best electric tankless heaters can deploy practically all of their energy towards heating water.
- Tank heaters are only able to provide consistent hot water when usage habits are predictable and stay within the limit of the tank. Adequately powered tankless heaters provide hot water as soon as you need it, for as long as you need it.
- Because they don’t store large amounts of water, tankless heaters won’t flood your basement or harbor dangerous bacteria.
Hello to efficient, modern heating
For most homes, tankless heaters beat out other water heating options when it comes to price, efficiency, and performance. Many of the units on this page are also near-silent, running at a similar volume to new kitchen appliances.
Here are the main benefits of owning a tankless water heater…
Energy efficiency
Thanks to their microprocessors, flow sensors, and conductive heating elements, tankless heaters can easily detect when hot water is needed and quickly convert energy into heat. This makes the vast majority of tankless heaters between 80% and 99% energy efficient.
Lower utility bills
According to the leading appliance certification board, Energy Star, the average household can save thousands of dollars over the lifespan of a tankless heater in comparison to a tank unit. While tankless heaters draw more energy when heating water, they heat on-demand, meaning they spend far less time in an active state.
Extended lifespan
Tankless heaters have an estimated lifespan of 20 years, which again is up to double that of traditional boilers. Beyond base lifespan, tankless heaters also require less maintenance on average. Instead of an annual service, tankless units simply need flushing to remove a buildup of hard water minerals—even this is unnecessary if you filter your water using a good quality water softener.
Endless hot water
When a tankless heater is correctly sized for a home’s needs (e.g. adequate flow rate and power capacity) it will provide hot water for as long as you need it. The best tankless heaters can even handle multiple appliances running at the same time without a perceptible drop inflow.
Save space
The storage tank of a traditional heater may be up to 60 gallons, which is a considerable size and takes up a large amount of floor space in an average home. The average size of a tankless heater is 28 x 20 x 10 inches, which means that they can be mounted to walls, hidden in cupboards, or even kept outside.
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