The 10 Best Tankless Water Heaters

I finally got fed up with our old 50-gallon tank water heater. The final straw was it giving up the ghost halfway through a shower on a cold January morning. Never again. We made the switch to a tankless unit two years ago, and the two best parts are endless hot water and a noticeably lower electric bill.

It’s a big upgrade, though. You can’t just grab one off the shelf. You have to think about your home’s electrical panel, whether you have gas, and how many people are using hot water at once. I spent a ton of time figuring all that out, so I put together this list of the best tankless water heaters I found for 2026 to make it easier for you.

 

 

Best Whole-House Tankless Water Heaters

These are the workhorses. They’re designed to replace that big tank in your basement and supply hot water to your entire house, from the showers to the dishwasher.

 

 

Stiebel Eltron Tempra 36 Plus

This one costs about $849. It’s a German-engineered beast, and it’s what you need if you have cold winters where the groundwater is practically ice.

The “Advanced Flow Control” is the real magic here. It keeps the water temperature rock-solid, even if someone starts the dishwasher while you’re in the shower. It’s also incredibly quiet. We barely know it’s running.

The Downside: This thing is an energy monster. You’ll need some serious electrical service to your house and space for three separate 50-amp breakers. This isn’t a simple swap; you’ll likely need an electrician to make sure your panel can handle it.

 

 

Rinnai RU180iN

At $1627, this Rinnai is a serious investment, but it’s built for big families with big demands. If you’ve got three bathrooms and a washing machine that never stops, this is your unit. It runs on natural gas and can easily handle multiple showers and appliances at once without breaking a sweat.

Rinnai is known for reliability, and they back it up with a 12-year warranty on the heat exchanger. That kind of peace of mind is worth a lot. It has a massive flow rate and is super efficient for a gas model.

The Downside: The upfront cost is high, and you absolutely need a natural gas or propane line. It’s not an option for an all-electric home without major plumbing work.

 

 

EcoSmart ECO 36

For around $600, the EcoSmart ECO 36 is one of the best whole-home electric options out there. It’s powerful enough for most families, even in colder climates, and can run a couple of showers and a sink simultaneously without any temperature drops.

It’s incredibly efficient at 99.8%, so you’ll definitely see the savings on your utility bill compared to an old tank heater. The self-modulating tech means it only uses the exact amount of energy needed, which is great.

The Downside: To get the full warranty, you have to have it professionally installed. It’s not really a DIY-friendly project if you want that protection, so factor in the cost of a plumber.

 

 

Rheem RTEX-36

Priced at $800, this is another powerful electric model that’s great for a smaller home or a large apartment. It puts out plenty of hot water, around 7 GPM, which is enough for a couple of showers and a sink at the same time.

I like the compact design. It doesn’t take up much wall space, and the digital controls make it simple to set the exact temperature you want. Rheem is a trusted name, and this unit is a reliable workhorse.

The Downside: Just like the other big electric heaters, it has huge power requirements. You’ll need to make sure your home’s electrical panel is up to the task before you buy.

 

 

Rinnai RL75iN

This Rinnai model is about $1400. It’s another fantastic gas-powered option for medium to large homes that need a reliable supply of hot water. It pushes out 7.5 gallons per minute, which is more than enough for a family of four.

The Japanese build quality is top-notch, and it comes with that great 12-year warranty. It’s a set-it-and-forget-it kind of appliance that you can count on for years.

The Downside: Because it’s a gas unit designed for indoor installation, you have to vent it to the outside. This can add a good bit of complexity and cost to the install, depending on where you locate it.

 

 

Rheem RTG Gas Tankless Water Heater

For about $1200, this Rheem gas heater is a fantastic all-around pick. It hits that perfect balance of performance, price, and reliability. It’s an outdoor unit, which means you don’t have to worry about venting through your roof or walls.

It can handle a big household with its 9.5 GPM flow rate. That means you can run the laundry, dishwasher, and a shower all at once. For a gas model, it offers tremendous value.

The Downside: Being an outdoor unit, it’s not ideal for extremely cold climates without proper freeze protection. And like any gas appliance, the installation is more involved than a simple electric plug-in.

 

 

Best Point-of-Use & Smaller Home Heaters

Sometimes you don’t need to power the whole house. These smaller units are perfect for a single bathroom, a remote sink, or a small apartment where demand isn’t as high.

 

 

Rheem RTEX-18

This one comes in at $449. It’s the perfect size for a small house, a condo, or even just boosting the hot water to a master bathroom. It provides enough flow for a shower and a sink in warmer climates, or just one shower in colder areas.

It’s super compact and the LED screen makes it easy to set your temperature. At 99.8% efficiency, it sips electricity instead of gulping it.

The Downside: It’s definitely not for a large family. If you try to run multiple showers or big appliances, it won’t be able to keep up and the water will go lukewarm.

 

 

Stiebel Eltron DHC 10-2

At just $250, this little guy is a problem-solver. I think of it for places like a workshop sink or a half-bath that’s a long pipe run from your main heater. You get hot water instantly without waiting for it to travel from the basement.

Stiebel Eltron has been making these things forever, and the quality is excellent. It’s a simple, durable unit that just does its job.

The Downside: This is strictly a point-of-use heater. Don’t even think about trying to run a shower with it; it’s designed for a single sink, period.

 

 

EcoSmart ECO 11

This is another great budget option at $250. It’s ideal for a single bathroom or a small apartment, especially if you live in a warmer state like Florida or Texas where the incoming water isn’t frigid.

It’s tiny, so you can mount it right in a closet or under a vanity, freeing up floor space. And like other EcoSmart models, it’s extremely efficient and can save you a good chunk of change on your bills.

The Downside: Its performance drops off a cliff in cold climates. If your groundwater is below 50 degrees, it will struggle to produce enough hot water for a satisfying shower.

 

 

Rheem RTX-06T

For $200, this is the perfect under-sink unit. I’ve seen these installed in guest bathrooms or for a kitchen sink to get immediate hot water for washing dishes. It’s small, efficient, and gives you that endless on-demand supply for a single fixture.

The digital control is a nice feature at this price point. You can dial in the exact temperature you want for hand washing or anything else.

The Downside: Even though it’s small, it’s not a simple plug-in appliance. It requires its own dedicated 40-amp circuit, which might mean you need to run a new wire from your breaker box.

 

 

What to Look For When Buying a Tankless Heater

Before you click “buy,” there are a few things you have to get right. Picking the wrong one means you’ll either have lukewarm showers or you’ll have spent way too much money on a unit you don’t need.

First, figure out your Gallons Per Minute, or GPM. This is just a measure of how much water it can heat at once. A standard shower head is about 2.5 GPM and a faucet is about 1 GPM. If you want to run two showers at the same time, you’ll need a heater that can provide at least 5 GPM.

Next is “temperature rise.” This is the most overlooked part. You need to know the temperature of the water coming into your house. If your groundwater is 50°F and you want your shower at 110°F, you need a heater that can handle a 60° rise. A heater that works great in Arizona might be totally inadequate for a home in Minnesota because the incoming water is so much colder.

Finally, be honest about your home’s infrastructure. For gas models, do you have a gas line nearby? For electric models, check your breaker box. The big whole-house units require a ton of power, often 200-amp service and multiple open slots in your panel. Always check the electrical requirements before you fall in love with a specific model.