Best Tankless Water Heaters of 2022, Buying Guide and Analysis

Best Tankless Water Heaters

Best Tankless Water Heaters of 2022, Buying Guide and Analysis

A tankless on-demand water heater heats water only when you need it. These heaters can install in a closet, on an exterior wall, or in another convenient location within your home. They can heat your entire home or a single point of use, such as a shower, sink, or appliance.

A natural gas tankless heater provides an endless hot water supply saves money on energy costs by not storing and reheating the same water tank. Although more expensive to purchase and fix upfront, most homeowners find enough energy savings that it pays for itself after a few years.

How does a tankless water heater work?

  • When you turn on a hot water faucet or turn on the dishwasher, the tankless heater recognizes the need for hot water and starts the healing process.
  • The incoming water temperature determines how much heat the burners must produce to deliver water at the desired temperature.
  • When we demand hot water stops, the unit collapses and stops using power, waiting for more hot water.
  • The bottom line: hot water isn’t limited to what’s available in your tank.
  • Buy water heaters
  • Accessories for water heaters
  • Buy shelter tanks

Advantages to having a tankless heater

  • Instant Hot Water: You can turn a regular water source into hot water on demand. You are not limited to what a storage tank heater can hold. Whether you’re doing the dishes, doing your laundry or taking a hot bath, or even doing it all at once, tankless water heater technology will deliver the hot water your immediate lifestyle demands.
  • Low energy bills: Take advantage of up to 40% electricity savings with a tankless water heater. Units are designed to be highly efficient by heating water only when needed.
  • Longevity: Tankless water heaters typically last up to 18 years, often twice as long as a particular tank-style unit.
  • Retrench of space: Conventional heaters can take up to 16 square feet of valuable floor area. Many tankless water heaters are suitcase size and can install on almost any wall inside or outside your home.
  • clean and fresh water: Conventional water heaters can build rust and scale inside the tank where the hot water you use for bathing and drinking is stored. With tankless water heaters, you’ll always get clean freshwater heated on demand as it passes through the unit.

Choosing the Right Tankless Water Heater

It is essential to determine how much tankless water heater you will need. A too-small heater will not adequately meet your home’s hot water needs, and having a too large heater is an unnecessary expense. How much hot water will you need during peak demand, when the dishwasher is running, while you are showering and doing a load of laundry? How much incoming water needs to be heated to meet demand?

Before buying a tankless water heater, consider two things: flow rate, which means water measured in gallons per minute (GPM) for fixtures or appliances, and rise temperature, which is the difference between the groundwater temperature and desired hot water outlet temperature.

Flow rate (GPM)

To determine your hot water needs, list the total number of appliances or fixtures you will use simultaneously during peak demand: kitchen sink use, laundry load, and shower at the same time. Then add each flow rate to the total flow rate.

Check the manufacturer’s manual for the appliance or appliance (showerhead, dishwasher, washing machine, etc.) for the flow rate, or check to see if the GPM is stamped directly on the item. You can easily calculate the GPM of an appliance or fixture with a bucket and a timer using the formula: 60 divided by the number of seconds it fills a 1-gallon container with water from a water heater or fixture.

Temperature increase

Groundwater temperatures vary across the country and range from the mid-30s to the upper 70s, measured in degrees Fahrenheit. North America is divided into three climatic zones with average groundwater temperatures:

  • North area: 37 degrees to 51 degrees
  • Ecuador: 52 degrees to 61 degrees
  • South Zone: 62 degrees to 77 degrees

Internal domestic water temperatures typically range between 110 and 120 degrees. Subtract the water temperature from the desired internal water temperature to determine the temperature rise. For example, if your inlet water temperature is 57 degrees and the shower water temperature you need is 120 degrees, the temperature rise is 63 degrees.

When shopping for a tankless water heater, in addition to being armed with flow and temperature rise, check out the sizing charts to guide you in choosing the heater that best fits your needs.

Point-of-use water heaters

Sometimes an additional hot water boom is needed in one area of ​​your home. That’s where a compact point-of-use (POU) water heater can help. For example, a POU heater can install nearby if you have a hot tube that uses electric heat. These small tankless heaters are installed near a room or appliance that requires additional hot water. These appliances are also helpful for additions/extensions to an existing home and can often install in a cabinet or other small space.

Hybrid water heaters

If you prefer a tank water heater but still want to lower your energy costs, a hybrid water heater may be the right choice for you. By combining a tank and tank-style water heater functions, these appliances are typically more than twice as efficient as they can install with your existing setup. Hybrid water heaters have a heat pump that draws in and circulates air around them, expelling cooler air back to the installation. The extra heating energy from the air means that conventional methods require less heat. These hybrid water heaters have high energy efficiency on demand.

Ten best tankless water heaters.

1. Rinnai V65eN Natural Gas Tankless Water Heater, 6.5 GPM

Best Overall

Great warranty

This extra-durable tankless water heater will keep your showers hot for years to come.

If you desperately need a hot shower, you don’t want to wait for the water to warm up. It is just plain frustrating. With this water heater’s 6.6 GPM, you can keep the hot water flowing to your heart’s content. The temperature-lock system prevents accidental temperature changes (and burns). And with the generous warranties for labor, heat exchanger, and parts, you can feel confident buying.

EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Auto-Modulating Technology, White

2. The EcoSmart ECO 27 Electric Tankless Heater features a digital controller that adjusts one-degree increments.

  • It offers the ability to heat up to three gallons of water per minute at an inlet temperature of 37 degrees or up to 6 gallons per minute in warmer climates.
  • It equips with stainless steel and copper components for increased durability.
  •  A thermostat includes with automatic reset.
  • It features a compact design with 17″ high x 17″ wide x 3.625″ deep overall unit dimensions.

3. Stiebel Eltron – Tempra 24 Plus – Electric Tankless Water Heater, On-Demand Hot Water, Eco, White, 20.2

Best Electric- Preset memory options

This tankless water heater’s digital display and preset memory options make it easy to keep your water temperature exactly where you need it.

Whether you like your showers steaming hot or merely lukewarm, the temperature of your water heater comes into play. And while many homeowners never think about it, having the proper temperature range is a critical factor in keeping your energy bills in check and preventing unnecessary maintenance. This tankless water heater ticks off all the boxes for being compact and powerful. And its digital display control makes it easy to adjust settings as you need quickly.

4. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray

Quietest- Powerful self-modulation

The powerful self-modulation on this tankless water heater means you might never have to face a cold shower again.

Many tankless water heaters try to be smart enough to figure out when you need more or less hot water but struggle to do so. With the self-modulation on this electrical tankless water heater unit, you don’t have to worry about increasing hot water needs. You’ll also save even more energy in the long run.

5. Rheem RTEX-24 24kW 240V Electric Tankless Heater, Gray

Easiest Installation- Compact but powerful

This powerful tankless water heater provides hot water to up to three showers.

Many tankless water heaters can take on warming up the shower for one person. But if you have multiple showers going on simultaneously, things can start to get tricky. This model can keep up to three showers hot simultaneously, so you don’t have to keep your bathtime on a timetable ever again.

Bosch Tronic 3000 T 7 Gallon Mini Tank Electric Water Heater (ES8) – Eliminate Hot Water Time – Shelf, Wall or Floor Mount

Standard Plumbing Supply

The Bosch Tronic 3000 tankless water heater offers point-of-use convenience for a kitchen or bathroom sink.

  • The ability to tap into your existing cold water line and install it under a sink or counter to provide hot water.
  • It equips with a pressure relief valve.
  • It has a glass-lined tank.
  • Includes CFC-free foam insulation to increase the unit’s energy efficiency.
  • Also available in two smaller sizes:
    • 2.5-gallon mini tank (ES2.5).
    • 4-gallon mini-tank (ES4).

6. Rinnai V75iN Gas Tankless Water Heater, 7.5 GPM

The Rinnai V Series HE Natural Gas Tankless Water Heater features thermaCirc360 technology that recirculates hot water through pipes.

  • Water flow rate up to 6.5 gallons per minute.
  • It features a compact design that can place in various locations around the home.
  • Equipped with WiFi monitoring.
  • It includes efficient heating coils that activate and heat the water on demand.
  • It comes with improved scale detection to reduce potential damage to the system.
  • Consists of a temperature lock to prevent unwanted changes to the unit.
  • It has up to 150,000 BTUs.

7. Eemax EEM24013 Electric Point-of-Use Tankless Water Heater

The Eemax EEM24013 is designed for point of use applications or small residences with minimal flow requirements.

These electric tankless water heaters provide endless hot water where you need it and when you need it. This product can use for your residential water heating needs. It is a 240 volt, 13-kilowatt unit. The EEM2401 is designed to use applications or a small apartment in warmer climates. It provides hot water for one sink in colder climates or shower in warmer temperatures.

  • Equipped with a dial and digital temperature control readout.
  • It offers 1 degree (F) temperature increments from 80 to 140 degrees (F).
  • A three-foot power cord includes for easy installation with it.
  • 1/2 inch CF connectors and NPT adapters come with it.

 Best Tankless Water Heaters: Buying Guide


The different tankless water heaters can depend on the ratings used. In the case of how water is heated, for example, there are condensed and non-condensed varieties. Then there are indoor and outdoor tankless heaters. There are also fixed and portable heaters. Please be aware of those rates before making your purchase.


Tankless water heaters will differ in size depending on where they install, how much water they can hold, and how much space you have. Larger water heaters will generally only be necessary for larger homes and apartments. Even the smallest or medium ones should suffice, especially in temperate areas.


How quickly a tankless heater can heat water will depend on its power and capacity. Even the ones meant to heat the water as you go will require some time to turn on, especially if you turn them off after each use. However, the best ones should take no more than a few minutes, while poor-quality heaters can take much longer.


One of the most basic features a tankless water heater should have is controlling temperature. After all, not everyone has the same tolerance for heat. On/off buttons must also be available, and the appropriate control interface to go along with them.


You should have no problem installing tankless water heaters yourself, as they are designed to be convenient. The only one that should have problems is the version that runs on gas. That one will require you to connect it to the propane tank pipe as well, but it’s just an extra step. If the heat seems too challenging to install, you can ask a professional to do it.

Types of Tankless Water Heaters for RVs


RV owners like electric tankless water heaters because they are environmentally friendly and very cost-effective. An RV electric tankless water heater is relatively easy to install, and you can use it with a Genset or solar panel. It is 98 percent efficient and does not contribute to greenhouse gas emissions.


An RV gas tankless water heater runs on propane or kerosene. It usually comes with power vents to release exhaust gases, and the vent is essential for proper operation. One problem is that a propane tankless water heater can release greenhouse gases. It is 85 percent efficient and less expensive than electric tankless water heaters.

no condensation

This tankless water heater uses a heat exchanger to heat water on demand. It is very trustworthy; however, a stainless steel vent is required for hot exhaust, expensive. It’s not particularly energy-efficient, mainly if you use a lot of hot water in short bursts.


These units use a second heat exchanger that reuses the heat from the exhaust to heat the water further. As a result, tankless condensing water heaters are 92 to 94 percent efficient. While PVC vents are inexpensive, the units are not very energy efficient when using water in short bursts.

RV Tankless Water Heater Prices

  • Under $200: A small water heater typically costs several hundred dollars, but you can find some models for under $200. These may be smaller in capacity and have fewer features than expensive models.
  • $200-$500: Some of the most popular tankless water heaters fall into this price. These are efficient enough to get the job done, but they are not very expensive.
  • Over $500: It’s common to pay a lot for a premium tankless water unit. Some cost up to $800 or more. These are also frequently used in small cabins and people who live off the grid.

key features


You should estimate your water usage before buying an RV tankless heater. That way, you will determine what size you need. The shower area uses between 1.5 and 3 gallons per minute, while the bathtub and toilet use between 2 and 4.5 gallons per minute, respectively. The kitchen sink can use about 1.5 gallons of water per minute.

water flow rate

The water flow rate of a tankless water heater is the amount of hot water it releases per minute. Most people use the heater when showering, so the best RV tankless water heater fits a typical family and can supply 1.5 to 2 gallons of hot water per minute.

Heating capacity 

The BTU is the heat capacity provided by a tankless heater. Groundwater temperatures vary by location, and cold groundwater can be more challenging to heat. Some units have between 30,000 and 50,000 BTUs, which is a bit smaller than what you get at home. A higher rating means a high-efficiency unit, which means the team can heat water faster.

Power supply

Tankless heaters run on natural gas, propane, and electricity, so check to see which source is available in your RV. If it is a single source, you must select a heater that uses that power source. If you have more than one energy source, such as electricity and gas, keep in mind that gas water heaters require more maintenance, and electric heaters are more expensive to operate.

Other considerations

  • Space: Space is prime real estate in your camper, trailer, or RV. As a result, you need to ensure that the water heater does not take up much space. Ensure you know the actual size of the heater to see if it fits correctly. Also, you may want one that is lightweight so you can easily maneuver it around.
  • Failsafe: A tankless heater for travel trailers and RVs should have some safeguards to keep it in good working order. It includes a design that prevents voltage shortages and spikes and accidental activation of the electronic ignition due to excessive heat. It should also have good features that protect it during bad weather and rough terrain.

Best RV Tankless Water Heater Reviews & Recommendations 2022


  • If you have a tankless heater that runs on propane, you may need to purchase stainless steel pipes to vent, which can be a bit pricey. These types of RV heaters also need to service annually.
  • Since RV water heaters are smaller than home water heaters, you shouldn’t spend too much time in the shower. You can temporarily turn off the water while shampooing your hair or lather your body to conserve water.
  • Drain the water tank before storing your RV for an extended period. To prevent pipes from freezing or cracking, be sure to winterize them.
  • If you take your RV out of storage, close the bypass valve. You must fill the tank before hitting the road because it can damage it if it gets hot without water.
  •  It is pretty inexpensive and can significantly extend the life of the tank.

Is a tankless water heater worth it?

A tankless water heater can be well worth it for those wanting to live a more sustainable lifestyle or for people who simply want to reduce their energy bills. And while tankless water heaters can cost more at first, in the long run, they save your money not only on utility bills but on the fixture itself. Because tankless models, on average, can last twice as long as their traditional counterparts, offering even more, cost savings on your investment.


  • Power Source: Tankless water heaters are most commonly powered by electricity or natural gas. In general, gas models have a more robust output, but the costs of the system and its integration into your home can be higher.
  • GPM: GPM stands for “gallons per minute.” Determining what you need this number to be is key to deciding if a tankless water heater is right for your home. To calculate this, you will need to assess how many appliances (and people, for that matter) will need hot water daily.
  • Location: Generally speaking, water heaters are best kept inside your home where they are safe from sunlight, rain, bugs, and other unwanted elements. However, both gas and electric models typically have outdoor options. You will need to ensure any venting is appropriately placed and that the water heater is intended for outdoor use. Additionally, you will have to confirm the water heater is kept as warm as possible, especially if you live in a cold climate. Check the manufacturer guidelines for specifics.
  • Connections: Depending on what kind of power source you choose for your tankless water heater, you might need more infrastructure. Gas units, for example, require venting, an electrical outlet, a gas line, and of course, a water supply connection. Electrical heaters will involve water connections and a proper wiring setup. You are not sure how to perform either of these installations, it is always best to hire a licensed professional.

Do tankless water heaters lower your bills?

Tankless waters are far better at efficiently heating water. The most significant benefit of owning a tankless water heater is that you will benefit from the considerable reduction they make on your utility bills. The Department of Energy estimates that on-demand water heaters save between 24-34% on energy efficiency. This cost savings can add up over the years. And since tankless water heaters are durable, you can look forward to using them for years to come.

Frequently Asked Questions About Electric Tankless Water Heaters

After reading through the information on essential considerations and reviewing the best options, you are certainly in a good position to decide on the electric tankless water heater for your needs. However, some questions may remain. Answers to many that come up regularly are provided below.

How does a tankless water heater work?

A flow sensor activates a heating element as soon as you turn on a faucet or shower. As soon as the water turns off, so does the heat. It is generally called “on-demand” water heating. No energy is wasted filling a tank with water you don’t need, which is more economical and environmentally friendly.

  1. Do electric tankless water heaters need to vent?

No, there is no carbon monoxide by-product. Usually speaking, that makes electric tankless water heaters considerably easier to install.,

  1. Can you still shower if the water heater leaks?

Yes, you can still take a shower. A standard tank water heater has the potential for a catastrophic leak. While an electric tankless water heater does not hold water in a tank, malfunctioning parts can cause small leaks that can damage water.

  1. What are the signs that your tankless water heater is shutting down?

Dirty water, especially if dust particles are present, is a sign of internal damage. Inconsistent performance and lack of response to power input are other indicators.

  1. How does an electric tankless water heater flush?

The process usually involves:

  • Turning off the water and electricity supply.
  • Removing the heating element.
  • Filling the internal chambers with white vinegar.
  • Rinsing.

Manufacturers often provide specific instructions for each model.

  1. How long do electric tankless water heaters last?

20 years or more can expect a helpful life, according to the US Department of Energy.

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