The 10 Best Tankless Water Heaters

Updated February 06, 2018 by Tina Morna Freitas

10 Best Tankless Water Heaters
Best High-End
Best Mid-Range
Best Inexpensive
We spent 47 hours on research, videography, and editing, to review the top options for this wiki. If you've ever had the unpleasant experience of the spray suddenly going cold on you in the shower, or wondered why most homes heat water constantly when it is only used occasionally, then it's time to consider a tankless water heater. Our selections include a variety of units that will not only save you money, but also provide an endless supply of comfortable H2O for your whole family. When users buy our independently chosen editorial picks, we may earn commissions to support our work. Skip to the best tankless water heater on Amazon.

10. SioGreen IR288

The moderately priced SioGreen IR288 is designed to be connected near the shower or sink and utilizes a long-lasting quartz heating element. It is a smart choice if you don't want to deal with the hassle and expense of installing a whole house unit.
  • corrosion-resistant
  • does not leave limescale deposits
  • requires professional installation
Brand SioGreen
Model IR-14K
Weight 9.6 pounds
Rating 3.7 / 5.0

9. Rheem RTEX-13

With an on-unit rotary thermostat and digital LED screen that displays the exact temperature, the Rheem RTEX-13 is an easy to use option. The temperature is adjusted in one degree increments and the unit can be hooked up to any standard 1/2" water connection.
  • fast hot water response time
  • best for point-of-use installation
  • only raises water temp 40 degrees
Brand Rheem
Model RTEX-13
Weight 9.1 pounds
Rating 3.6 / 5.0

8. Eccotemp FVI

The Eccotemp FVI only runs when you need it, effectively saving you money at all times. It is perfect for a small house or vacation cabin, where the need for hot water is either infrequent or low in volume and you don't expect more than two showers to run together.
  • sleek housing has a small footprint
  • includes a stainless steel vent kit
  • makes a noticeable humming noise
Brand Eccotemp Systems
Model FVI-12-LP
Weight 32.6 pounds
Rating 4.1 / 5.0

7. Takagi T-KJR2

The Takagi T-KJR2 runs on natural gas and is intended for indoor installation only. It has a 6.6 gallon per minute flow rate, which makes it ideal for radiant heat applications or smaller homes where hot water will be used in multiple locations simultaneously.
  • relatively easy to self-install
  • has altitude settings
  • need to purchase a vent separately
Model T-KJr2-IN-NG
Weight 37.7 pounds
Rating 3.7 / 5.0

6. Rheem RTG-84

The Rheem RTG-84 is perfect for outdoor installations in cold climates, as it offers freeze protection down to as low as -30 degrees Fahrenheit. It has a 0.4 gallon-per-minute minimum activation flow rate and features next generation burner technology.
  • eligible for federal tax credits
  • low nitrogen oxide emissions
  • runs on propane
Brand Rheem
Model RTG-84XLN
Weight 54 pounds
Rating 4.4 / 5.0

5. Rinnai Ultra Series

The versatile Rinnai Ultra Series runs on either natural gas or propane and provides hot water up to 140 degrees. It can be converted for commercial usage and meets nitrous oxide emissions standards for both California and Texas.
  • pressure relief valve
  • operates very quietly
  • causes small dip in water pressure
Brand Rinnai
Model RUC98iN
Weight 84 pounds
Rating 4.0 / 5.0

4. EcoSmart Eco 27

Ideal for smaller families who don't expect to have more than two showers running at any given time, the EcoSmart Eco 27 can heat up to three gallons per minute and comes in at a budget-friendly price. It can save you up to 50% on water heating costs.
  • digital display panel
  • durable steel and copper components
  • not ideal in extremely cold climates
Brand EcoSmart
Model ECO 27
Weight 17.6 pounds
Rating 4.8 / 5.0

3. Takagi T-H3

With an output of 10 gallons per minute, the Takagi T-H3 is powerful enough to send hot water to three bathrooms in cold climates and four bathrooms in warmer climates, so you'll never wind up taking a cold shower, even if the kids and wife hit the bathroom first.
  • no pilot to keep lit
  • requires a separate valve kit
  • very expensive but high quality
Brand Takagi
Model T-H3-DV-N
Weight 66.3 pounds
Rating 5.0 / 5.0

2. Camplux 5L Portable

The convenient Camplux 5L Portable was designed especially for outdoor living. Low water pressure isn't a problem for this unit as it can function with as little as 2.5 PSI. It comes with showerhead and water hose attachments, and has a fold-down handle for easy carrying.
  • battery operated ignition option
  • can be installed indoors
  • anti-freeze protection
Brand Camplux 5L Portable
Model AY132
Weight 14.4 pounds
Rating 5.0 / 5.0

1. Stiebel Eltron Tempra

The compact Stiebel Eltron Tempra has a slim, sleek design that is about the size of a briefcase. This unit has advanced flow control even when multiple showers are running, and a hinged cover that offers quick access to the internal components if needed.
  • runs on electricity
  • does not require venting
  • maintains a steady temperature
Brand Stiebel Eltron
Model Tempra 36 Plus
Weight 22 pounds
Rating 4.6 / 5.0

A Tankless Job Is A Job Worth Doing

Fans of the hit television series Breaking Bad (and I promise no spoilers here) may remember an episode in which Walt, the main character, uses his illegally acquired money to make much needed repairs on his house. The repairs become a kind of metaphor for his desperate attempts to fix his relationships with his wife and son, and, as a result, they become an obsession.

During one of several trips to the home improvement store, a sales clerk asks him about the water heaters at which he's looking. Walt inquires about tankless models, and the clerk, presumably working on commission, lights right up.

That moment is based on the very real fact that tankless water heaters are more expensive than their enormous counterparts, but if you're willing and able to take the plunge, they'll save you a lot more money in the long run.

For starters, tankless heaters don't store a big tank full of water–hence the moniker tankless.

Traditional tank heaters have to keep that large body of water at a constant temperature so that a certain amount of hot water is available at all times. If you use up that tank of hot water, you have to wait for the new water coming into the tank to heat up.

That means you're spending more time and gas keeping many gallons of water hot even when you might not be using them. That's something called standby heat loss, and it's a gouging sword in the guts of your gas bill.

Tankless heaters, by contrast, circulate a flow of incoming water past a heat exchanger and back out the unit, heated and ready to go. There's no residual energy loss, and there's an endless supply of hot water. Gas models require additional ventilation, which is expensive to set up, and electric models will certainly raise your electric bill, but the savings will undeniably be present, and the average tankless heater will outlive a traditional heater by five to ten years.

No Tank Doesn't Mean No Options

At first glance, going tankless might seem like a simple change. After all, the only difference is that you're nixing the tank in favor of the much smaller heat exchanger. Well, it turns out there are some important differences to consider among tankless water heaters that could make or break your purchase and installation.

Tankless water heaters come in two main categories: gas and electric. Electric models use an electrically powered heat exchanger, which is a hefty tax on your power bills, but nothing compared to the cost of standby heat loss.

Gas powered tankless heaters come divided into two subcategories. There are your standard models, which require a basic ventilation system, and then there are condensing models which double the number of heat exchangers. That's great if you only have the one tankless unit to supply a whole house with hot water, but they require additional ventilation construction, as well as a condensate drain to evacuate the unit of moisture.

You're going to need to take a look at the available gas lines coming into your property before choosing a gas powered tankless water heater, as they may require a larger intake pipe than you currently have. If that's the case, it's going to be much less of a hassle to go electric. For the time being, electric will be more expensive, but natural gas costs are projected to surpass electricity costs in the coming years.

America Is Slow To Go Tankless

Say what you want about the US; there's a lot of space here. Sure, some of our cities are ridiculously overpopulated and many of our rural ares are equally underpopulated, but when you average it all out, there's a lot of room to breathe.

That's why a lot of American things are simply bigger than they are elsewhere in the world. Streets and the cars that drive on them, buildings and their work forces, houses and their families–all on the large side compared with the majority of the developed world.

It's no surprise, then, that even though we had our hands on tankless water heating technology in the late 1800s, we opted to standardize large tank water heaters in homes throughout the land. We had the space for it, so why bother economizing?

Now that gas and electricity are becoming so expensive, a lot of homeowners in the US are finding different ways to save on their energy costs, one of which are these tankless heaters. They've been immensely popular in Europe and the East for ages, so it was only a matter of time before our economic reality and their convenience merged.

The best part is that units in the US are priced to appear as a luxury item. People view tankless water heaters as a status symbol, a marker of the savvy and wealthy homeowner. As demand increases, unit prices are sure to come down, but now's the time to get in on the trend. It's never to soon to start saving.

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Last updated on February 06, 2018 by Tina Morna Freitas

Tina Morna Freitas is a writer who lives in Chicago with her family and two cats. She enjoys making and sipping margaritas and aspires to be a crazy cat lady once all the children are grown.

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