If you are researching tankless water heaters, then you have probably already heard about most of the benefits they have to offer. For example, a tankless water heater can reduce your water heating bill by as much as 24% to 35% - if your household uses less than 41 gallons of hot water each day. It is likely you are also familiar with the fact that they possess the potential to offer an unlimited source of continuous water.
Because they are not restricted by a tank size, there are no limits to the amount of water you can access. In short, purchasing a tankless heater is one of the smartest investments you can make in your home.
For decades, tankless water heaters have been the standard in Europe and other parts of the world; however, only in the last decade has North America seen a significant increase in interest. The downside to this newfound interest is that the market has quickly become saturated with many models as manufacturers hurry to jump on the bandwagon.
Unfortunately, many companies have cranked out their versions of tankless water heaters without investing the time and effort required to properly develop and engineer them. This oversaturation of the market makes it difficult to determine which models are worthwhile. Moreover, because tankless models have a high upfront cost, the stakes are high to pick the perfect model for your home.
The good news is that you have come to the right place! We have invested the time, read all of the tankless water heater reviews - and have done all the research for you.
Here is your one stop resource for all of the information you need to make an informed buying decision. Whether you live by yourself or are a member of a large family, we will help you find the perfect model that suits your individual needs, tastes, and budget.
5 Best Tankless Water Heaters for 2019
ECOSMART ECO 27
RHEEM RTE 13
The EcoSmart ECO 27 is one of the industry’s best-selling whole home tankless water heaters. Because it is a whole home model, it can be installed anywhere in a home and still provide service to the entire residence. Utilizing EcoSmart’s patented Smart Technology, this model conserves an impressive amount of energy while still providing adequate amounts of hot water for medium to large size residences – even during the harsh months of winter. A digital control panel allows the user to raise or lower the temperature of the water in one degree increments.
In addition to its customizable controls and ability to produce water on demand, one of the biggest selling points of the ECO 27 is its energy savings. Although this model is not Energy Star certified, it does boast an impressive 99.8% energy efficiency rating. In most instances, it will reduce a home’s energy costs by 50%. For a few homeowners, the savings have been so significant that the water heater has paid for its initial cost within a matter of a few months.
- EcoSmart offers a lifetime warranty on parts.
- The unit has a 99.8% energy efficiency rating.
- Digital temperature controls allow complete control of the water in one degree increments.
- This model is designed to provide endless hot water to larger households.
- All of its components are made from either stainless steel or copper to ensure their longevity and durability.
- This model can reduce a home’s energy consumption by up to 50%.
- Designed for cold climates, the ECO 27 can produce 3 gallons of hot water a minute.
- The temperature controls allow the temperature to be set between 80 and 140 degrees Fahrenheit.
- Its overall performance is affected by the temperature of the incoming water.
- Should a homeowner choose to install this tankless water heater themselves, EcoSmart will not honor the lifetime warranty on components.
Initially released in 2010, the Takagi T-KJr-IN-NG is the smallest, most compact water heater offered by Takagi. However, its small size does not mean it lacks power. It is more than capable of meeting the needs of a small apartment or home with one or two bathrooms. This model offers the same capabilities and features of a traditional unit with a 40 gallon tank. It has a maximum flow rate of 6.6 gallons per minute. This wall mounted model will supply hot water to appliances and plumbing fixtures. Additionally, it can also support radiant floor heating applications, as well as hydronic baseboards.
Although cost efficient, the Takagi T-KJr-IN-NG does not sacrifice versatility for price. It can be converted into a direct vent model by using the TV10 conversion kit (sold separately). This conversion kit allows the unit to be installed in a utility closet, garage, or other location where air supply might be restricted.
- The Takagi T-KJr-IN NG has an impressive maximum flow rate of 6.6 gpm.
- Outlet and inlet thermistors offer continuous monitoring of the hot water’s temperature.
- Takagi offers a 10 year warrant on the heat exchanger and a 5 year warranty on the parts.
- This model is Energy Star certified.
- The water heater works well with hard water.
- It has a BTU of 140,000 and an energy factor of 0.81-0 .83.
- The unit must be installed by a licensed technician. If the buyer chooses to install it themselves, Takagi will not honor the warranties.
- In order to install this unit, 4” Cat 3 stainless steel venting is required, which may result in an additional expense to install it.
The Rinnai RUC98iN is designed to provide you with an endless supply of water whenever you need it – even for multiple applications. The compact size of this wall mounted unit allows it to be stored in non-traditional locations, like attics and crawl spaces. Energy Star certified, the RUC98iN is available in 5 different BTU options, ranging from 130,000 to 199,000. The unique design of this model enables it to deliver hot water to your home much more quickly via its integrated recirculation pump and internal bypass line. A dedicated return line is not an absolute necessity.
One of the biggest selling points of the Rinnai RUC98iN is that it is the only tankless model on the market that offers dual pipe PVC or concentric polypropylene venting options on the same unit. This venting configuration options makes this unit particularly popular among dealers and installers. Moreover, this model features isolation valves, which make performing routine maintenance much simpler.
- The Rinnai RUC98iN offers two different venting options: PVC or concentric.
- It is Energy Star certified with an Energy Factor of .96.
- It has a max BTU of 199,000.
- The RUC98iN produces ultra-low NOX emissions.
- The space saving design of this model allows it to be installed almost anywhere in your home.
- The manufacturer provides a 12 year warranty on the heat exchanger, a 5 year warranty on the components, and a 1 year warranty on labor.
- Users have praised the fact that this unit is ultra-quiet when it is operating.
- A small percentage of buyers have experienced drops in water pressure when more than one showerhead is running in the home.
- Rinnai’s customer service department can be slow to respond to inquiries.
Small, discreet, and efficient, the Takagi T-KJr2-IN-LP has a lot going for it. It is important for prospective buyers to note that this unit is powered by propane gas, and it cannot be converted to anything else. It can reach temperatures of 150 degrees Fahrenheit and higher. In moderate climates, the T-KJr2-IN-LP can heat an average of 6.6 gallons per minute. In colder climates, this output will drop to an average of 3 to 6 gpm. There are switches on the water heater that allow the user to adjust the temperature of the hot water, but the model also comes with a convenient remote – a feature that users have particularly enjoyed.
The Takagi T-KJr2-IN-LP has a max BTU rating of 140,000, and it is equipped with outlet and inlet thermistors for continuous temperature monitoring. This model is Energy Star certified, and it has an Energy Factor of 0.81-0.83. Takagi offers a 10 year warranty on the heater exchange and a 5 year warranty on its components; however, the manufacturer will only honor these warranties if the unit is installed by a certified professional.
- The T-KJr2-IN-LP has a max flow rate of 6.6 gpm, making it ideal for powering multiple outlets at once.
- Weighing only 38 pounds, the compact and space saving design of this unit allows it to be installed almost anywhere in your home.
- Category 3, 4” stainless steel venting is required to install this unit.
- For the output it provides, the Takagi T-KJr2-IN-LP has an affordable price tag.
- It offers convenient and adjustable settings for the water temperature and water flow.
- The inclusion of the thermistors minimizes the occurrence of water pressure fluctuations.
- This model is not suitable for large homes.
- It cannot be converted to anything other than propane.
5. Rheem RTE 13
Rheem tankless water heaters are among some of the most popular models currently on the market, and the newest introduction to their lineup is the Rheem RTE 13 Electric Tankless Water Heater. It is designed primarily for point of use applications. Intended for single shower applications, this unit has a max hot water output of 4 gallons per minute. This model has an adjustment dial on the front to allow the user to adjust the water’s temperature as needed. One particularly unique feature of the RTE 13 is the inclusion LED status lights on the front of the unit, which indicate if it is in active or standby mode.
The RTE 13 weighs a mere 7.3 pounds and measures 7.2” x 7.2” x 7.2”. Because of its “ultra-compact” design, it can be installed almost anywhere in one’s home. Although the unit does come with an installation manual, Rheem will only honor the warranties it offers if the model is installed by a professional, licensed individual.
- LED lights indicate standby mode and active element.
- The heat exchanger is crafted from copper and brass to ensure its durability and longevity.
- The unit has a standard half inch water connection.
- The maximum flow rate for this model is 4 gallons per minute
- The 4 gpm flow rate is impressive for a single shower application.
- A sizable percentage of buyers have had the unit pay for itself within an average of 18 months.
- The thermostat dial used for adjusting the temperature offers nine different settings.
- The purchase of this unit includes a 6 gauge, 2 foot pre wired power cable.
- Rheem only offers a 1 year warranty on the parts of the RTE 13, which is considerably less than the warranties their competitors offer.
- Due to its point of use design, the places where it can be installed in the home are limited.
What is a Tankless Water Heater & How Do They Work?
In its most basic definition, a tankless water heater can be defined as an energy efficient type of water heater that produces hot water only as is needed. Because they do not have an attached tank, they do not experience the standby energy losses that traditional storage water heaters do. This conserves both energy and money.
A tankless water heater uses a heating element to heat water directly eliminating the need for a tank. When the hot water element of a faucet is opened, cold water travels to the unit via a pipe. The water is heated by either an electric element or a gas burner. Because of this technology, a tankless water heater can provide your home with an continuous supply of water. It eliminates the need to wait for a traditional 40 gallon tank to fill up with water. However, the output of a tankless water heater is limited by the flow rate of the incoming cold water.
The average tankless water heater will be able to produce approximately 2 to 5 gallons of hot water each minute. A gas or propane powered model will have higher flow rates than even the best tankless electric water heaters; however, there will be times when the largest gas powered models will be unable to meet demand. For example, if the washing machine is being run at the same time someone is taking a shower in the bathroom, a tankless water heater will be stretched to capacity. The solution to this problem would be to install two or more tankless water heaters in parallel with one another so they may simultaneously meet the demand for hot water.
Another option would be to install different tankless water heaters throughout your home for the appliances, like the dishwasher or washing machine, that require a significant amount of hot to warm water.
How Do Tankless Water Heaters Match Up to Traditional Tank Water Heaters?
Understanding the differences between a tankless water heater and a traditional storage heater can be summed up in these categories:
Energy efficiency is one of the primary reasons why an increasing number of homeowners are making the switch to tankless, and this is where the biggest significant difference between the two models exist.
- Storage water heaters with a tank are continuously running. Even when no water is being used, the unit is still using electricity to warm the water it has stored in its tank. That is wasted energy that you are paying for.
- Because a tankless water heater provides hot water only on demand, it conserves energy. The compact design and small size flash heats the water as it is needed.
The single largest problem that homeowners have with their water system is running out of hot water, but this problem is limited to tank size. Due to its on demand style of operation, a tankless model doesn’t have this issue.
- A tankless water heater only begins to heat water when a faucet is opened. Within a few seconds, it can raise the temperature of the water to the desired output, and there is no limit to the amount of hot water it can provide.
- The amount of water that a tank water heater can produce is limited to the amount of preheated water it can hold in its tank. If all of the water in the tank is used up, you’re simply out of luck. You must wait until the water heater can refill its tank and reheat the water.
Maintenance & Installation
The cost of installing a tankless water heater can be costly, and this is one of the primary deterrents that make people shy away from embracing this technology. However, as tankless heaters grow in popularity, the cost is slowly beginning to come down.
- Tank water heaters are an outdated technology, and their design is flawed. As a tank is repeatedly heated and cooled, minerals begin to accumulate inside of it. Most traditional water heaters have a lifespan of 5 to 12 years. The average industry warranty for this type of water heater is 6 years.
- Tankless water heaters are significantly more effective. They require a minimal amount of maintenance, and the average lifespan of a tankless heater ranges from 15 to 20 years. The average industry warranty for a tankless model is 15 years.
A Cost Analysis: What to Expect
As with traditional water heaters, prices for tankless water heaters run the gamut from under $1,000.00 to over $3,500.00. According to the website of the U.S. Department of Energy, an electric tankless water heater will save a homeowner an average of $44.00 per year, while a gas or propane powered models will save an average of $108.00 each year. Modern tankless water heaters have a median lifespan of 15 to 20 years. Traditional tank water heaters generally cost in the vicinity of $400.00 to $650.00 and have an average lifespan of 8 to 12 years. Regardless of which option one chooses, water quality, routine maintenance, quality of the installation, and the design and location of the unit will affect its longevity.
If your home is already equipped with the technology required to install a tankless water heater, then you can expect professional installation to cost you in the neighborhood of $750.00 to $1,000.00. If it is not, then be prepared to spend an average of $2,000.00 in addition to the cost of the unit itself. Installation of a tankless water heater requires the following:
- A dedicated gas line that is capable of handling the BTU demand
- Category III, 4 inch steel (the industry standard) venting
- Additional piping if the unit must be relocated
- A dedicated power source with a backup battery
If installation requires the unit to be located outdoors or attached to an exterior wall, then the installation cost can climb even higher. If you are in the process of building a new home, experts strongly encourage you to go ahead and equip your home with the technology required – even if you are only considering buying a tankless water heater. In the long run, it will cost you less.
Dispelling the Myths
The rise in popularity of tankless technology has also led to a rise in misconceptions and myths surrounding them. Before you decide to rush out and buy a tankless water heater, read on to find out the truth about some myths surrounding tankless water heaters.
1. You can simply swap out your traditional hot water heater for a tankless model.
Unfortunately, tankless and storage water heaters differ in their electrical needs, venting requirements, and gas line sizes. Retrofitting is not as straightforward as switching the models. Proper installation by a licensed professional is required to ensure peak performance and safety. A licensed professional will also be able to obtain the necessary permits to install the model.
2. Tankless water heaters heat water to unsafe temperatures.
This is a myth. All modern tankless water heaters are equipped with adjustable thermostats so that users may adjust the temperature to their liking. The thermostat acts as a safeguard against overheating and scalding. The water heated by your tankless water heater will not become unbearably hot unless the thermostat has been set too high.
3. Tankless water heaters deliver instant hot water.
Each tankless model will have a delay before it begins to produce hot water. Generally, this delay is no longer than 15 to 30 seconds – depending on the size of the water heater. The unit requires this time to turn itself on and gauge how much heat it must generate based upon the flow rates. Where the unit is installed in one’s home will also affect how long the delay is. To combat this issue, some homeowners opt to install multiple tankless water heaters or a circulation system to preheat the incoming water.
4. Tankless water heaters are inefficient.
Traditional water heaters have an affixed tank for storing water, which is kept hot via a pilot light. Because the pilot light is always on, it uses a significant amount of energy. For this reason, tank water heaters have a considerably bigger carbon footprint than their tankless cousins. Because it utilizes clean energy at minimal use, a tankless water heater is an eco-friendly option.
5. A tankless water heater won’t supply my home with enough hot water.
A traditional water heater with a 40 gallon tank holds exactly 40 gallons of water. Once those 40 gallons have been used, more water must be reheated. This process can take as long as 30 minutes, which translates to limited availability.
However, a tankless water heater will supply water as long as it is needed. Because there is no storage tank, there is no shortage of hot water. The water is warmed as it passes over the heating element to an outlet. All you have to do is open the faucet. For example, a medium sized whole home tankless water heater will provide enough hot water for four to five people. Since the water is heated on demand, two or more people can shower at one time.
Difference Between Point of Use & Whole House
When homeowners begin shopping for tankless water heaters, one of the first questions they ask is, “Do I need a whole home or point of use model?”
Point of use tankless water heaters are commonly seen in bathrooms and kitchens across Europe, but they are not as popular in North America. A point of use model is more efficient than its whole home cousin because there is a shorter distance between the unit and the fixture it is supplying water to. This reduces the amount of hot water used each time a faucet is opened and eliminates piping losses. With a longer pipe, after you have finished using the water, you have simultaneously used the “hot” water left in the pipe. You have paid for the energy required to heat that water.
Point of use models are smaller than whole home models, and because they are not designed to supply more than one location at a time, they use smaller heaters. Installation costs are usually less expensive than with a whole home model; however, they are primarily intended for small residences. If you own a large home or have a big family, then purchasing a single whole home tankless water heater might be more practical and cost efficient than purchasing multiple point of use heaters. One of the primary reasons why these models are not popular in North America is aesthetics. Many homeowners simply do not like the idea of having a visible water heater in their bathrooms or kitchens.
By comparison, a whole home tankless water heater is a single unit that is designed to provide hot water to an entire household. They are generally installed where a home’s storage water heater was located, so they are not visible to residents. Although they do require significantly more electricity or gas to heat water than one or two point of use models, they are still quite energy efficient. The primary downside to choosing a whole home model is that it will require larger than standard gas pipe (for gas models) or a dedicated electrical service line (for electric models). These requirements can add to the unit’s overall installation cost.
What Size Do I Need?
Properly sizing a tankless water heater for your home is not difficult, but it does require a bit of thought and effort.
1. What is your maximum flow rate?
Although tankless water heaters are often touted as providing an continuous supply of hot water, the party will come to an end if the flow rate exceeds the unit’s ability to heat the incoming water. Simply put, as the demand for water increases (called the flow rates), the water heater’s abilities to adequately heat the water will decrease.
When sizing a tankless hot water heater, the flow rate is one of the factors that must be accounted for. Most on demand water heaters are generally rated based upon the maximum rise in temperature they can provide at a given flow rate.
The flow rate is defined as the specific amount of water that must be heated when using a tankless water heater. It is measured in gallons per minute. If your water heater will need to service multiple applications at once, the max amount of flowing water that the system can adequately heat will need to be calculated. You should never attempt to undersize a tankless water heater in a bid to save money.
Let’s say that you are looking for a point of use tankless water heater that can service a bathroom sink’s water faucet and a showerhead at the same time. The sink faucet has a flow rate of 2.1 gallons per minute (GPM), and the showerhead has a flow rate of 2.8 GPM. In this instance, you will need to look for a tankless water heater that can accommodate a flow rate of 4.9 GPM.
2. Calculate the temperature rise.
Temperature rise is defined as the difference between the incoming water’s temperature and the wanted outcome. For example, if you live in the Southern United States, the average temperature of watering entering into your home’s hot water system would be around 65 degrees Fahrenheit. This number will fluctuate wildly from one climate to the next; however, ground temperature is generally on par with the average yearly air temperature for a given region or community.
After you have familiarized yourself with the incoming water’s temperature, this number should be subtracted from the output temperature you would like to have. For the majority of domestic tasks, like taking a shower or washing clothes, a sufficient temperature output would range from 100 to 120 degrees Fahrenheit. From an average temp of 65 degrees, incoming water would need to be heated by another 55 degrees Fahrenheit in order to reach the top of the target output range.
3. Does your tankless water heater meet your heating requirements?
After determining the flow rate and calculating the temperature rise, your next step will be to start researching specifications for different models of tankless hot water heaters to figure out which size best suits your requirements. The sizing and rating specifications for a standard tankless water heater would be listed as something like 10 gallons per minute (GPM) with a temperature rise of 55 degrees. New tankless water heaters are equipped with smart technology that enables them to self-limit their flow rates in order to meet an established temperature. Although still relatively rare, this models are becoming increasingly popular.
Can I Install It Myself?
In short, you can try…but unless you are a licensed plumber AND electrician, you probably shouldn’t.
There are specific requirements that must be followed when it comes to properly installing a tankless water heater. If you fail to meet the established requirements, it could put your safety in jeopardy, lead to faulty operation, or void the manufacturer’s warranty. Although most manufacturers do provide installation instructions for their water heaters, an increasing number of manufacturers are opting not to honor the warranties they provide if the unit is not installed by a licensed professional.
Requirements for installation will be affected the brand you choose to purchase, the type of unit, and local laws and ordinances. For examples, many communities require homeowners to obtain permits if they decide to install propane or gas powered tankless water heaters. This type of water heater almost always has special venting requirements. A gas powered tankless water heater utilizes fans that pull in air from the outdoors, and it expels gasses via a flue system. Vents may need to be located on a sidewall or the roof. If you plan on purchasing a propane or gas powered model, be prepared to pay for home renovations to accommodate the required venting system.
For tankless water heaters that are powered by electricity, an upgrade to your home’s existing electrical system may be required. It is imperative for your home to have the proper amount of electrical capacity to power the water heater. Most electrical models require their own dedicated power line.
Most manufacturers also have specific requirements regarding where in the home a tankless water heater can be installed. For example, your new water heater will need to be installed in a location where, in the event of accidental leakage, nearby structures and floors will not be affected. Tankless water heaters must be installed in a location where air flow will not be restricted and is well-ventilated.
For these reasons, it is best to skip the DIY route and spend the money to hire a licensed professional to install your tankless water heater. In doing so, you will ensure your own safety and that of your family. You can also rest assured that the manufacturer will honor their warranty.
Pros & Cons
Space saving designs, endless supplies of hot water, and decreased energy bills are just a few of the reasons why an increasing number of homeowners are switching over to tankless water heaters; however, for some individuals, these benefits are not sufficient to entice them to make the switch.
As with most items you’ll buy, tankless water heaters have their own sets of pros and cons.
The upfront cost can be astronomical.
On average, a tankless water heater will cost three times more than a tank model. Depending on the type you purchase and its size, the cost can range from just under $1,000.00 to well over $3,000.00 – and that is just for the unit itself. You must also pay the cost of having a professional plumber install it.
Another factor to consider is that not all homes are equipped to accommodate a tankless water heater. For homeowners who purchase an electric model, their home’s electrical system may need upgrading, which means that money will need to be spent to hire a qualified electrician. It is not uncommon for rewiring your home to add as much as $5,000.00 to the total cost of installation.
Tankless water heaters have longer warranties and save space.
For the majority of homeowners, the benefits of having a tankless water heater extend far beyond the energy savings. Modern tankless heaters have small, compact designs, which minimize the amount of space they take up. They can also be installed in non-traditional locations, like crawl spaces and attics if there is room. Because they have a significantly longer lifespan than traditional water heaters, they are better for the environment since a tank won’t end up rusting in a landfill.
Moreover, tankless water heaters are generally accompanied by longer warranties. The average manufacturer’s warranty lasts for 15 years, but it is not uncommon for warranties to be as long 20 years. By comparison, storage tank water heaters have an average warranty of just six years.
There are temperature fluctuations and cold climates to contend with.
Regardless of whether you choose a whole home or point of use model, you can expect a drop off in water temperature when your unit(s) are tasked to provide hot water to multiple applications at the same time. Some homeowners choose to mitigate this effect by installing multiple point of use models in bathrooms and kitchens, but this will add to overall purchase and installation cost of the heaters.
If you live in a cold climate, you may have no choice but to purchase a gas powered model in order to avoid poor performance from an electrical model. Using a tankless water heater in a cold climate also requires additional maintenance during the winter months, like completely draining the pipes on freezing nights in order to avoid cracked and leaking pipes.
They supply you with an endless amount of hot water and increase your home’s value.
Tankless water heaters will produce an endless amount of hot/warm water because they never run out of cold water – so long as the total water demand does not exceed the unit’s max flow capacity rate.
Although high initial installation costs are often viewed as a negative, they should also be viewed as an investment in your home. Because they are considered green technology, installing one or more of these units in your home will increase its resale value.
Although tankless water heaters are growing in popularity, many homeowners still have reservations about investing in one. The technology is still in its infancy, and people are often cautious when it comes to buying the new and unusual. While this is certainly understandable, don’t let your concerns keep you from missing out on all that they have to offer.
The first step is to make the decision to buy a tankless water heater. The second step is to choose a model that meets your unique needs. The third and final step is to have it installed by a qualified professional.
Simply by following these three steps, you’ll be able to enjoy the benefits of owning an efficient and eco-friendly water heater that will provide you with many years of service.