The 10 Best Tankless Water Heaters

Updated October 04, 2017 by Brett Dvoretz

10 Best Tankless Water Heaters
Best High-End
Best Mid-Range
Best Inexpensive
Ever had the unpleasant experience of the water suddenly going cold on you in the shower? Or wondered why most homes constantly heat water that's only used occasionally? Yeah, us too. So we found these tankless water heaters that not only save you money, but also provide an endless supply of hot water 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. EcoSmart ECO 11

Small and affordable, the EcoSmart ECO 11 is suitable for areas with limited space, such as small apartments or RVs. Despite its low cost, they haven't skimped on features and it still offers digital temperature control in one-degree increments.
  • can handle two sinks or one shower
  • straightforward installation
  • not suitable for cold weather areas
Brand EcoSmart
Model ECO 11
Weight 7.9 pounds
Rating 4.1 / 5.0

9. SioGreen IR288

The extremely affordable SioGreen IR288 is meant to be connected near the shower 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.
  • self-cleaning maintenance-free use
  • can be used in campers and boats
  • doesn't get extremely hot
Brand SuperGreen
Model IR-14K
Weight 7.1 pounds
Rating 3.7 / 5.0

8. Rheem RTEX08

With an on-unit rotary thermostat and digital LED screen that displays the exact temperature, the Rheem RTEX08 is an easy to understand and 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 RTE 9
Weight 8.1 pounds
Rating 3.6 / 5.0

7. Takagi T-K4-IN-NG

The Takagi T-K4-IN-NG runs on natural gas and is intended only for indoor installation. It has an 8 GPM maximum flow rate, which makes it more than suitable for large families and medium-sized 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
Brand Takagi
Model T-K4-IN-NG
Weight 42.8 pounds
Rating 3.9 / 5.0

6. Eccotemp FVI-12-LP

The Eccotemp FVI-12-LP only runs when you need it, effectively saving you money at all times. It is perfect for smaller homes or vacation cabins 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.
  • independent gas and water controls
  • sleek housing has a small footprint
  • includes a stainless steel vent kit
Brand Eccotemp Systems
Model FVI-12-LP
Weight 32.7 pounds
Rating 3.9 / 5.0

5. Rheem RTG-84XP

The Rheem RTG-84XP 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 before it starts heating water.
  • eligible for federal tax credits
  • low nitrogen oxide emissions
  • can self-diagnose problems
Brand Rheem
Model RTG-84XP
Weight 56.2 pounds
Rating 4.0 / 5.0

4. Rinnai RUC98iN

The Rinnai RUC98iN is intended for indoor installation and accepts a 15,200 to 199,000 BTU input range. It is suitable for residential and commercial use, and meets California's and Texas' NOx emissions standards, so you can rest easy that it is good for the planet.
  • comes with a pressure relief valve
  • operates very quietly
  • adjustable max temperature setting
Brand Rinnai
Model RUC98iN
Weight 84 pounds
Rating 4.0 / 5.0

3. Stiebel Eltron Tempra

The Stiebel Eltron Tempra is a reliable option that requires no venting and easily fits on almost any wall thanks to its slim and sleek design. It has a hinged cover that offers quick access to the internal components if needed.
  • runs on electricity not natural gas
  • simple control interface
  • maintains a steady temperature
Brand Stiebel Eltron
Weight 21.4 pounds
Rating 4.8 / 5.0

2. EcoSmart ECO 27

Ideal for smaller homes or 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
  • compact and easy to mount
Brand EcoSmart
Model ECO 27
Weight 17.6 pounds
Rating 4.5 / 5.0

1. Takagi T-H3J-DV-N

With an output of 10 gallons per minute, the Takagi T-H3J-DV-N is powerful enough to send instant hot water to three bathrooms in cold climates and four bathrooms in warmer climates, so you'll never wind up taking a cold shower if the kids and wife hit the bathroom first.
  • highly efficient condensing tech
  • manufactured in japan
  • virtually no hot gas exhaust
Brand Takagi
Model T-H3-DV-N
Weight 66.3 pounds
Rating 4.7 / 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 October 04, 2017 by Brett Dvoretz

A wandering writer who spends as much time on the road as behind the computer screen, Brett can either be found hacking furiously away at the keyboard or perhaps enjoying a whiskey and coke on some exotic beach, sometimes both simultaneously, usually with a four-legged companion by his side. He hopes to one day become a modern day renaissance man.

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