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Running out of hot water on a cold winter’s day can make you shiver. Discovering that your old, tank-style water heater has finally kicked the can can feel, well, cold. Receiving an end-of-month energy bill that your bank account is sure to feel a bit frosty about is also not so fun. Luckily, it’s possible to solve all three problems at once by purchasing a tankless water heater. Hot Water Heater With Recirculating Pump
Tankless water heaters forgo a traditional tank in favor of heating water on demand. This increases energy efficiency and saves money and space at the same time. If you’re thinking of getting a tankless water heater installed to help you through the winter months and need help making a decision, check out our top 10 list of best tankless water heaters below.
We developed our list of the best tankless water heaters by first identifying competitors that met basic criteria, then reviewing the 27 most widely available water heaters from that list and scoring them all based on 19 different attributes. We further pared our list down to the top 10 tankless water heaters. Our ratings take into consideration factors like pricing at the time of scoring, customer rating, max GPM, heating capacity (BTUs), ETL certified and Energy Star certified. All ratings are determined solely by our editorial team.
Why you can trust Forbes Home: The Forbes Home team is committed to bringing you independent, unbiased ratings and information. We use data and expert advice to inform all of our content. Plus, our advisory board of licensed professionals fact-checks and reviews our content for accuracy and relevancy.
Enjoy Significant Energy Savings With Tankless Water Heaters
For endless hot water when you need it, and energy savings, consider a tankless water heater installation from a top-rated company on Angi.
First up is the EcoSmart ECO 27 tankless water heater. It makes the top of our list for its $437price tag and 92,128 BTUs of heating capacity at 99% efficiency. EcoSmart is a trusted name for pool heaters, so they know how to heat water. This heater supplies up to 6.5 gallons of hot water per minute using 27kW of electricity. Although, if the inlet water is very cool, the hot water output can go down to about 2.7 gallons.
Powerful enough for a family of four or five at its peak, it also features self-modulating technology which lowers electrical consumption when its full power isn’t needed. EcoSmart shows its confidence by offering a lifetime limited warranty.
Rheem 18kw Tankless Electric Water Heater
For two-person families, or for an excellent point-of-use heater, Rheem’s 18kW Tankless Electric Water Heater offers the solution. Using 18kW of electricity to generate 61,419 BTUs, it can produce up to 4.4 gallons of hot water per minute.
Rheem has been a hot water industry leader for nearly 100 years and stands behind their products with a five year warranty on heating components and one year on any other parts. It’ll cost you $395and will require two forty amp circuit breakers to operate. Not bad for a water heater rated at 99.8% efficient with self-modulating technology to save you even more money.
Stiebel Eltron DHC Trend Point-of-Use Electric Tankless Water Heaters
For point-of-use heaters, Stiebel Eltron’s line of DHC Trend Point-of-Use Electric Tankless Water Heaters is our favorite. It’s third overall on our list. We’ve reviewed the DHC 10-2 to prove our point. At $165for 32,757 BTUs using 9600 watts, and heating up to 6 gallons of water per minute, it’s no wonder why we like it.
There are several models to choose from so you’ll be able to find one that works for your home. All of them are covered by 10 years of warranty protection against leaks and three years for defects. They all protect themselves from damage with a flow rate monitor that’ll cut power to the unit if the water supply is interrupted.
Rheem 13kw Tankless Electric Water Heater RTEX-13
Our next offering is another high-quality electric tankless water heater from Rheem. The reason it’s a little lower on our list is because it bills itself as both a whole house water heater and as a point-of-use water heater. At 44,358 BTUs it would struggle to heat enough water fast enough for even a small family. As a point-of-use water heater though, it’s great.
$245buys you a smaller replica of Rheems 18kW Tankless Electric Water Heater. The features are the same as the larger model, but this one has less electrical demand requirements and common ½ inch plumbing connections for easy installation. Temperature is adjustable in one-degree increments and it’s able to provide up to 3.17 gallons of hot water per minute.
The Eemax 27kW Electric Tankless water heater easily makes our list with its whole-house water heater for a family of four or five for $479. Hot water production ranges from 3 to 7 gallons per minute with adjustable, single-degree accuracy from 80 to 140 degrees Fahrenheit. Electrical use is kept in check by adjusting power demands based on water flow.
Eemax provides five years of warranty protection against leaks and one year of protection on all other parts. For 27,000 watts of power though, space for three new circuit breakers will be required for operation.
Rinnai RU160iN RU Model Series
The first natural gas fueled water heater on our list is the Rinnai RU160iN Model Series, tanking our sixth place spot. Up to 9 gallons per minute of hot water can be supplied by this 160,000 BTU workhorse. It’s Energy Star rated at a 93% efficiency rating and costs around $1,463.
Rinnai claims a 100-year commitment to quality. This shows in its warranty: 15 years on heating components, five years on parts and one year on labor is among the best warranties of the products in our review. Quiet, small and manufactured in the U.S.A. round out the reasons we’re impressed.
Stiebel Eltron Tempra® Plus Whole House Electric Tankless Water Heaters
The Tempra Plus Whole House Electric Tankless Water Heater lineup from Stiebel Eltron is next on the list. Priced a little higher than its closest competitors, at $649for a 24kW water heater, it still makes a good impression. It produces up to 5 gallons of hot water per minute with 22,500 BTUs with an efficiency rating of 99%.
This one is excellent for use as a whole house heater for small families of four or less. Otherwise, it may be a little underpowered. The German company offers seven year leakage protection and three years of warranty against workmanship and materials.
Titan N-120 Tankless Water Heater
Do you live in a warm climate? The Titan N-120 Tankless Water Heater may be just what you need. It’s a good whole house water heater for locations where the supply water is 65 degrees Fahrenheit or warmer. It’s a$245electric tankless water heater that heats 2.15 gallons of water per minute at 60,000 BTUs using 11,000 watts of electricity.
For locations that are a little cooler, the N-120 can serve as a powerful, wall mounted, point-of-use water heater with digital display and easy controls. Titan provides a warranty of 10 years on water components and one year on parts.
Rinnai RU199iP RU Model Series
The RU199iP RU Model Series from Rinnai is a beast, providing as much as 11 hot gallons of water per minute with 199,000 BTUs. It’s propane powered, so it’s not for every home, and at $1,750, it’s a little pricey. It’ll hardly be heard in a large house with it’s mere 48dB sound emission.
It made our list for Rinnai’s excellent warranty. The warranty is 15 years on heating parts, five years on other parts and a year covering labor charges.
Being just barely beaten back from ninth place to tenth is the Noritz EZ111 Series tankless water heater. $1,665gets your home a 199,900 BTU, propane-burning monster that can heat up to 11.1 gallons of water per minute.
It carries an Energy Star certification and runs at 97% efficiency. Noritz has been a pioneer in providing electronically controlled water heaters since 1981. Their 25-year heating component warranty, along with five years parts and one year labor, is the best of our review.
Before getting a tankless water heater, figure out two major elements related to what kind of heater you’ll need: How much hot water you plan on using, and what kind of power source is available to you.
How much hot water do you need? Do you plan on a whole-house heater, where the hot water supply will be accessible from any location in your home? Or do you plan on just supplying hot water at certain points (also known as point-of-use)? Depending on your answer to this question, you’ll be better able to determine what kind of tankless water heater you should purchase. You can expect whole-house heaters, due to their larger capacity, to cost more on average than a smaller point-of-use heater.
Tankless water heaters typically draw power from one of three sources: electricity, natural gas or propane. Depending on which source you opt for, your tankless water heater may be more or less expensive—to purchase, to install and to use. In general, electrically powered water heaters are the most common option but may come with high energy costs. Natural gas-powered water heaters have low energy costs but cost more upfront.
Most importantly, you may be limited by what type of power is available to your location. Always check the details before purchasing your water heater: If only electricity is available to you, for example, you will have to buy an electrically powered water heater.
Deciding what kind of tankless water heater you’ll need is surprisingly straightforward. Though you should also consider factors like your budget and whether or not you’ll have enough space to install your heater, here are some of the most important points to think about.
As noted above, two main types of water heaters exist: whole-house heaters and point-of-use heaters. Once you decide which one you need and what type of power source you’ll be using, you’ll find your options have already started to narrow.
Capacity refers to the amount of hot water a tankless water heater provides, measured in gallons per minute. Depending on where and how you will be using hot water (i.e. point-of-use versus a whole-house heater), you can calculate how much water you’ll need and then determine the required capacity and size of your new tankless water heater. For electrically-powered tankless water heaters, capacity will be expressed in kilowatts; for gas-powered heaters, look for BTUs (British Thermal Units).
Finding the flow rate for your household is key to determining your tank’s ideal capacity. The flow rate is a measure of how much hot water you’ll be using at peak demand, measured in gallons per minute. Figure out what appliances or fixtures you’re most likely to be using simultaneously, then add together their individual flow rates to calculate the total flow rate.
If you don’t want inconsistently delivered hot water, your new tankless water heater will have to be able to meet or exceed this demand. You can typically find the flow rate of an appliance or fixture in the product’s specifications or on the manufacturer’s website.
Temperature rise refers to the difference between local groundwater temperatures and your desired hot water temperature. This then informs how much energy must be used in order to heat your water. A large temperature rise of 70 degrees (from 50 degrees Fahrenheit to 120 degrees Fahrenheit), for example, will use more energy than a temperature rise of 40 degrees.
Depending on where you live, the temperature of the groundwater can vary significantly. Predictably, warmer regions have higher groundwater temperatures. Similarly, you also have some control over this factor depending on your hot water settings. An energy-efficient tankless water heater should be able to handle temperature rise with the least amount of energy possible.
If you’re on the fence about making the switch to a tankless water heater, here are a few points to help you decide if it’ll be worth it.
Tankless water heaters are also known as instantaneous water heaters, and for good reason: They are able to supply hot water on-demand, whenever you need it. Gone are the days of running out of cold water in the middle of your shower, or waiting a few hours for your tank to refill and reheat before running the dishwasher: hot water is available to you at any time.
By far the most popular benefit to having a tankless water heater is its energy efficiency. Since water heaters only use electricity on demand, they aren’t running up a huge electricity bill—saving you money while also being more environmentally friendly (especially if your electricity source is renewable). In fact, despite its high upfront cost, a tankless water heater will pay for itself in a couple of years thanks to lower energy bills and a long lifespan.
Because tankless water heaters are, well, tankless, maintenance is significantly easier than it would be for a traditional tank heater. You also don’t have to worry about issues like tank corrosion or water damage, which may be a weight off your mind. Tankless water heaters are also easier to repair or replace if something does go wrong.
However, it’s still necessary to perform maintenance at least yearly in order to keep your water heater in tip-top shape. While you can easily perform this maintenance yourself, a professional plumber can also get it done in no time flat.
Depending on the water chemistry in your location, you may need to flush your tankless water more than once annually. Or, for areas with particularly hard water, consider installing a tankless water heater with descaling abilities to minimize maintenance requirements.
Regardless of the size of your tankless water heater, the unit is still guaranteed to be smaller than an entire tank-style heater. If you’re short on space or simply want to free up some extra spots for storage, changing to a tankless water heater will save you plenty of room.
With regular maintenance, tankless water heaters can last as long as 20 years—a significant return on your investment. In comparison, a tank-style water heater will only last between eight and 12 years, even with maintenance.
Compare Quotes From Top-rated Water Heater Installers
To determine the best solar pool cover ranking, the Forbes Home Improvement editorial team analyzed 27 major tankless water heaters, with each water heater’s star rating determined by evaluating a variety of metrics, including:
Price accounts for 35% of the best tankless water heaters overall ranking. The editorial team evaluated a multitude of price points for each water heater on platforms like each product page, Lowe’s, Home Depot and Amazon.
Customer rating data accounts for 35% of the total ranking and includes ratings from platforms like the BBB, Trustpilot, Consumer Affairs, Facebook, ReviewMeta and more.
According to Energy.Gov, the average water heater’s flow rate should be at least 3.25 gallons (or 12.3 liters) per minute. Each tankless water heater’s GPM (max) was evaluated and gained or lost it points depending on the flow rate.
Each tankless water heater’s heating capacity in BTUs accounts for 10% of the total tankless water heater ranking.
An ETL certification officiates proof of compliance, which means the water heater is safe and healthy to use in your home. Whether or not a tankless water heater is ETL-certified caused it to lose or gain points totaling 5% of the total ranking.
Energy star certification signals efficiency and potential savings to a homeowner’s energy bill, which is why this category covers 5% of the total ranking. Whether a tankless water heater is energy star certified either gained or lost it points.
Flushing a tankless water heater helps keep your water heater working efficiently and increases its lifespan. Here are the basic steps to follow, assuming you’ve bought a flushing kit to help you with the process:
Tankless water heaters come with some downsides. A unit can have high upfront costs for installation and purchase. They also may cease to work during a power outage, and they can have difficulty heating enough water for multiple outlets (for example, if you have the dishwasher, shower and laundry machine running simultaneously).
Yes, you can take a shower with a tankless water heater as long as you are not simultaneously running another appliance that uses a lot of hot water. If you have, for example, the dishwasher running at the same time, you may experience unpleasant temperature fluctuations during your shower as your water heater tries to meet the high demand. Modern plumbing may, but not always, include specialized valves to control these fluctuations. If you live in an older house without updated plumbing, expect the discomfort.
Theoretically speaking, no, you can’t run out of hot water with a tankless water heater since the hot water is supplied on-demand. But you can overwhelm the water heater by forcing it to provide hot water in multiple locations simultaneously, resulting in lukewarm water.
Yes, a tankless water heater can easily work for an entire house as long as it is not overwhelmed by simultaneous demands for hot water in multiple areas. If this occurs, you are likely to receive lukewarm water at all locations. Otherwise, though, a tankless water heater will likely function without issue.
Choosing the right size for your tankless water heater depends on multiple factors, mainly temperature rise and peak hot water demand. Once you have determined these two things, you can check with water heater manufacturers in order to find a model that matches your needs.
Chauncey grew up on a farm in rural northern California. At 18 he ran away and saw the world with a backpack and a credit card, discovering that the true value of any point or mile is the experience it facilitates. He remains most at home on a tractor, but has learned that opportunity is where he finds it and discomfort is more interesting than complacency.
Having spent 30+ years in residential construction, contracting, remodeling, maintenance and home repair, Deane now contributes DIY, informational and financial content as a freelance writer and consultant for several publications. Throughout his career, he strived to assist his clients in finding the potential hidden within the walls of every home and empowering them to take control of their household repair and remodeling endeavors. Deane’s primary career goal involves sharing home-related knowledge and providing self-sufficiency tools to as large an audience as possible.
Central Heating Circulating Pump Samantha is an editor who covers all topics home-related including home improvement and repair. She edited home repair and design content at websites like The Spruce and HomeAdvisor. She also has hosted videos on DIY home tips and solutions and launched multiple home improvement review boards staffed with licensed pros.