Best RV Tankless Water Heaters of 2021

A warm shower after a day of exploring is the stuff — we’ve found the best RV tankless water heaters for you.

Do you love to spend the summer camping? Or maybe you enjoy the open roads while driving in your RV — nothing beats the freeing feeling. After a long day of exploring, a warm shower can be very tempting.

However, an RV water heater tank — usually only about 6 gallons — can be problematic if there are several people. An on-demand heater might just be the solution you want since it heats water as you need it.

Our Top Picks

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Product Comparison Table

Product Image of the EcoSmart 8 KW Electric Tankless Water Heater, 8 KW at 240 Volts with Patented Self Modulating Technology
Best for Eco-Friendly Camping
EcoSmart 8KW Heater
  • Smart technology
  • Easy-to-use digital thermostat
  • Space-saving design
Product Image of the Stiebel Eltron Tankless Heater – Tempra 12 Plus – Electric, On Demand Hot Water, Eco, White
Best for Larger RVs
Stiebel Eltron 12 Heater
  • Produces lots of hot water
  • Energy efficient
  • Conveniently quiet
Product Image of the Camplux 2.64 GPM Tankless Propane Water Heater, Outdoor Portable Gas Water Heater with Overheating Protection, Instant Propane Hot Water Heater for RV, Camping, Cabins, Barns, White
Best for Off-Grid Camping
Camplux Tankless Water Heater
  • For off-grid camping
  • Easy hanging and transportation
  • Includes most of needed equipment
Product Image of the Tankless Water Heater Electric 240V, ECOTOUCH 5.5KW On Demand Hot Water Heater with Remote Control Digital Display,Electric Instant Hot Water Heater,Overheating Protection,Black
Best for High-Tech RVers
EcoTouch Electric Heater
  • Sleek compact design
  • Touch panel and remote control
  • Easy installation
Product Image of the Eemax EEM24018 Electric Tankless Water Heater, Blue
Best Aesthetically Pleasing
Eemax EEM24018 Heater
  • Beautiful design
  • Prevents excessive energy waste
  • Compact

How to Choose a RV Tankless Water Heater

Tankless water heaters are a great addition to your RV. They connect to your onboard water tank to enable them provide you with hot water on demand. But before you buy a tankless water heater for your RV, we have made a list of some things worth considering.

Water Capacity and Cost

Most standard storage RV water heaters have a tank with about 6 gallons capacity. You can also have a 10-gallon appliance; however, this is more of an upgrade, and it requires more space.

A common problem with this water storage design is the recovery time; a 10-gallon heater can take up to an hour to heat up. If you’re traveling with friends or family, there will be some waiting time between showers.

An advantage of a tankless heater is that it doesn’t have any recovery time. It heats the water on-demand when you need it. As soon as you turn on the faucet, burners ignite within the unit, heating the cool water as it passes.

The initial price of a tankless water heater is more than standard units. However, it’s more than worth it if you’re a group traveling regularly. It also won’t use as much electricity or gas since it only turns on when needed.

Over time, this energy-saving will probably recoup the cost of the initial extra outlay.

Water Consumption and Flow Rate

Knowing approximately how much hot water you use on a regular basis can help you buy the right heater. Buying a large unit that takes up space and money when it isn’t necessary is no fun. However, having a unit that cannot keep up with your needs is also a waste of money.

Before buying a unit, we suggest trying to figure out how many places within your RV you’ll need hot water. For instance, the bathroom requires hot water for showers. The kitchen needs hot water for dishes, and maybe even a dishwasher or washing machine.

Tankless water heaters suited for RV’s will usually provide you with two to six gallons of hot water per minute. The exact number depends on the model you choose. After figuring out your water consumption, choose the appropriate heater.

When looking at tankless water heaters, you’ll want to check its water flow rate. The flow rate is the amount of hot water the unit will provide per minute. It should be stated on the label.

Now, in an RV, the majority of hot water is used in the bathroom for showers. Therefore, you actually won’t need to buy the biggest model. Units with a 2 to 2.5-gallon flow rate should be enough for the average family of four.

Fuel Type

How you’re going to power your tankless water heater is an important consideration. Tankless units usually come as gas or electric, and each has its pros and cons. Keep reading and see which one would suit you.

1. Electric

An electric tankless water heater is the most cost-effective as well as the most environmentally-friendly option.

These are quick and easy to install in your RV. They can be powered by your campground’s electrical source when parked.

On the road, it can operate from your RV’s electrical system. Using solar panels to help charge is a great way of staying environmentally friendly. If you don’t have solar panels, an external generator is an alternative.

The electric unit itself doesn’t emit greenhouse gasses, although a generator does.

2. Gas

Since you won’t have access to natural gas in your RV, this type of heater requires propane or kerosene.

Even though a gas-powered unit is cheaper than an electric, it comes with an alternative cost. The heater does release a certain amount of greenhouse gasses which are harmful to the environment.

You might be thinking that you’ll need to be buying a lot of propane. However, a tankless heater uses less propane compared to a standard tank unit. This is because it doesn’t need to keep water at a set temperature.

Don’t Forget

It’s crucial with a gas unit to have some venting since an RV is such an enclosed space. Always leave a vent open whenever the heater is working.


When traveling in an RV, power shortages or spikes can happen, especially when parked at a campsite. Some tankless models will have features that protect it against any sudden changes. Excessive temperatures can also sometimes trigger an electric ignition, but a good unit will be protected.

Types of RV Tankless Water Heaters

One more thing you might want to consider is the type of unit. For an RV, you can choose between two types: portable and home system. Let’s take a closer look.


Product Image of the Camplux 2.64 GPM Tankless Propane Water Heater, Outdoor Portable Gas Water Heater with Overheating Protection, Instant Propane Hot Water Heater for RV, Camping, Cabins, Barns, White

A portable tankless water heater is what it claims; portable. This type of unit is super easy to take on the road, and you can even use it when camping. These are great for moderate hot water usage, for example, a daily hot shower.


  • Portable: It doesn’t have to sit in your RV permanently. You can easily take it outside. Some models even allow you to connect a shower head directly to the unit.
  • Easy installation: Portable units don’t require complicated piping or wiring. They’re fairly easy to install, and if you’re handy, you could install it anywhere within the RV.
  • Inexpensive: Portable tankless water heaters are cheaper than more permanent units.


  • Won’t be enough for simultaneous use: Portable heaters may be cheaper, but they also won’t be enough for more than one source at a time.

Home Systems

Product Image of the EcoSmart 8 KW Electric Tankless Water Heater, 8 KW at 240 Volts with Patented Self Modulating Technology

Fitting a home system tankless water heater in your RV will require professional help. As you might guess from the name, it’s a whole system which has to be installed. However, if your hot water consumption needs to be high, it’s worth it.


  • Good for high demands: If you’re traveling as a group, a home system is worth it. It will be able to keep up with your needs and even simultaneous use.
  • High flow rate: These types of heaters also have a higher flow rate, which means you’ll get more hot water faster.


  • The initial price is higher: Home systems are generally higher priced, and you also need to pay for installation, but it can definitely be worthwhile.

Benefits of a Tankless Water Heater

Having a tankless water heater in your RV can save you much space. However, there are many other great benefits to look forward to. Let’s go through a few.

  • No cold showers: Since there’s no tank to empty, you won’t have to worry about running out of hot water. The tankless water heater delivers hot water on demand, so all you have to do is turn on the hot faucet.
  • Conserves water: The tankless heater will begin to heat the water as soon as you decide you need it. It also heats the water a lot quicker, which limits the amount of water wasted.
  • Saves space: The compact size of a tankless water heater makes it the perfect choice for an RV or trailer. You can also place it in multiple locations — some RVers will even install a small unit underneath the kitchen sink.
  • Provides clean water: Water left in a tank can lead to corrosive effects contaminating the water, causing unpleasant odors, rust, and stains (1). The tankless heater won’t be storing any water, so no worries about musty-smelling stagnant liquids.
  • Longer service life: A tankless water heater is an investment. It should be able to last you for many years. If you have a portable unit, you could even use it underneath a sink inside your house as well.
  • Better warranty: A tankless model usually holds a warranty of 10 to 15 years instead of the general 10-year on a standard unit. They’re actually known for having a lifespan of 20 years, depending on water quality and maintenance (2).


If you do notice a decrease in your hot water flow, we highly recommend that you flush your unit. You can purchase specialized solutions which will quickly get rid of any scale build-up. Or you can use white vinegar to clean out the unit.

The Best RV Tankless Water Heaters of 2021

Here are the top five RV tankless water heaters on the market.

1. EcoSmart 8 KW Electric Tankless Water Heater

Best Tankless Water Heater for Eco-Friendly Camping

Spending time in your RV is all about being close to nature. So why not include an eco-friendly boiler? This electric tankless water heater from EcoSmart is the perfect candidate.

We love the innovation of this product. It utilizes a self-modulating technology, meaning that it adjusts the input of energy to the amount of hot water needed.

It also features a digital temperature control that enables you to set the perfect temperature — in 1-degree increments. The unit is space-saving compact — measuring 12 inches by 8 inches.

Although EcoSmart mainly designed this as a whole-home boiler, it works just fine as a point-of-use heater under your sink. The unit will heat around 1.5 gallons per minute to a temperature of 105 degrees Fahrenheit.

The only drawback is that it doesn’t perform well in colder conditions. In this case, the gallon per minute will likely decrease to a slower flow.

Why We Love It

Excellent Use of Smart Technology

The use of smart technology in this unit is mind-blowing. It features one of the most innovative self-modulating technologies accessible today. The boiler will adjust its energy demand based on the amount of hot water you’ll need.

Additionally, it features durable, threaded heating elements that heat the water quickly and efficiently. Plus, EcoSmart claims that they’re easy to replace.

Easy-To-Use Digital Thermostat

The digital thermostat is an excellent feature to have. You can adjust it in 1-degree increments. This allows you to set the exact temperature you require — whether for a shower or the dishes.

Space-Saving Design

This tankless water heater from EcoSmart is space-saving convenient. It’s compact and would fit perfectly in any size RV. The heater measures just under 12 inches in height — approximately 11.5 inches by 8 inches with a depth of 3.75 inches.

The unit requires at least a 100-amp electrical panel and a 40-amp double pole circuit breaker.

Keep In Mind

Not Ideal in Colder Climates

If you’re planning on spending the cold winter months in your RV, then this tankless water heater isn’t your best choice. EcoSmart recommends that you avoid buying it if you’ll be using it in conditions colder than 67 degrees Fahrenheit.

If you must use it in conditions colder than 67 degrees Fahrenheit, make sure that you place it just where you need it. This will help it deliver hot water more effectively.

Additional Specs

Measurements 11.5 inches by 8 inches by 3.75 inches
Flow rate 1.5 gallons per minute
Temperature range 80 to 140 degrees Fahrenheit
Weight 5.3 pounds
Warranty Limited lifetime warranty

2. Stiebel Eltron 12 Plus Tempra Tankless Water Heater

Best Tankless Water Heater for Larger RVs

If you’re spending your vacation in a larger RV such as a fifth wheel, then this might be for you. This tankless water heater from Stiebel Eltron is both sleek in design and capable of producing an endless flow of hot water.

They designed this boiler as a whole-house unit. This means that it is competent of producing hot water for two running showers and one sink.

Depending on your inlet water temperature, it has a flow rate of 1.3 to 2.5 gallons per minute. Additionally, the unit has an energy factor of 0.99 with no standby heat loss. It also has maximum energy savings thanks to its self-modulating technology.

Stiebel Eltron is a pioneer in the industry — producing their first unit 90 years ago — so this boiler won’t disappoint. It’s conveniently quiet, which is perfect for the RV. The unit also features a digital, easy-to-operate, display.

Why We Love It

Produces Lots of Hot Water

This unit is more than capable of producing a lot of hot water. It works on-demand, supplying you with an endless flow. The flow rate depends on your incoming water temperature.

If you’re traveling to where inlet temperatures don’t exceed 52 degrees Fahrenheit, the flow rate is 1.3 gallons per minute. In warmer regions where temperatures readily exceed 62 to 72 degrees Fahrenheit, the flow rate is 2.5 gallons per minute.

It also features a flow-rate control. This feature reduces the flow rate if your hot water demand increases, for example, when taking a shower.

Energy Efficient

Stiebel Eltron prides themselves on producing units with an energy factor of 0.99. The reason behind this is the unit’s advanced auto-modulation technology. This function adjusts the power input according to the flow rate — essentially saving tonnes of energy.

Conveniently Quiet

When living in an RV, the last thing you want is a noisy appliance. This unit is whisper quiet when it operates — excellent for a peaceful holiday.

Features a Digital Display

One of the things we love about this unit is the digital display. It shows you exactly what you need to see to maximize your energy savings. It basically eliminates the guesswork when it comes to temperature settings.

Another reason why we chose their plus model, is because it features some additional functions. On the display, it has pre-set temperature buttons and memory settings. The plus unit also features water flow and savings monitors that constantly provide you with valuable information.

Keep In Mind

Not Easy to Install

The plumbing is pretty straightforward and most users say that they installed it themselves. Most also warn not to mess with the electricals though, since this is more complicated. So, unless you have electrical knowledge, you’ll have to contact a professional to come and wire it.

Additional Specs

Measurements 14.5 inches by 16.2 inches by 4.5 inches
Flow rate 1.3 gallon to 2.5 gallons per minute
Temperature range 86 to 140 degrees Fahrenheit
Weight 13.5 pounds
Warranty Seven-year warranty

3. Camplux 2.64 GPM Tankless Propane Water Heater

Best Tankless Water Heater for Off-Grid Camping

Off-grid camping, or boondocking, is a popular way of getting away from all the hustle and bustle of everyday life. You become dependant on yourself and your camper — not a ready-made campsite. This tankless gas water heater from Camplux is excellent for just that.

The unit is slightly different from the rest on our list — it’s actually a small, outdoor shower. It consists of the “tank” itself that you connect to a gas regulator and inlet water. It then heats the water on-demand where the water exits through the attached shower head.

It’s perfect for smaller RVs or campers without a shower, such as teardrops and foldable campers. It comes with a handle that you can hang on any wall for convenience, or for carrying when you’re moving it. Along with the heater, you’ll get most of the pipes and hoses needed to use the unit.

Why We Love It

Great for Off-Grid Camping

If you’re planning a little get-away in your mini teardrop camper, then this unit is perfect. It’s made for outdoor use, where you simply connect it to the water source and propane gas — then enjoy your shower.

Large Handle for Easy Hanging and Transportation

The large handle enables you to hang the heater wherever you find most convenient. It also allows you to move the unit more easily. It’s not too heavy either, weighing about 18 pounds.

Most of the Needed Equipment Is Included

Along with the unit, you’ll receive:

  • Pedestal and shower head.
  • 5-feet shower hose.
  • 5-feet CSA approved gas hose and regulator.
  • 0.5-inch BSP female times 0.75-inch GHT female garden hose.
  • 0.5-inch BSP female times 0.75-inch GHT male garden hose.
  • 0.5-inch BSP female times 0.625 NPT inverted flare male gas inlet connector.
  • Water tape and screws.
  • Instruction manual.

Keep In Mind

Not for Use in Enclosed RVs or Campers

Because this is a gas-powered unit, it requires ample room for combustion and ventilation. Hence, if you’re planning on installing this inside your RV, make sure you have proper ventilation.

Low-Quality Shower Hose Included

Some users pointed out that the included shower hose is of poor quality. Most recommend that you replace it with a more durable one before leaving for your trip.

Additional Specs

Measurements 12.8 inches by 6.1 inches by 21.65 inches
Flow rate 2.64 gallons per minute
Temperature range Not specified
Weight 18 pounds
Warranty N/A

4. EcoTouch Tankless Water Heater Electric

Best Tankless Water Heater for High-Tech RV's

We live in a world full of smart technology — so shouldn’t that include your water heater? This one from Ecotouch is both sleek and compact — about the size of an oatmeal box. We chose the black model since it blends in nicely with any decor.

It features a digital display with a touch control panel and remote control — making it super convenient. What’s more convenient is its 360-degree installation. You can install it in any position and it will still fully function.

The unit also features smart modulation of power input. Based on your temperature setting and flow rate, the boiler adjusts its power needs. This essentially prevents you from scalding yourself as you reduce the flow from the tap.

Why We Love It

Sleek Compact Design

As mentioned above, we chose the black model — you can also get it in white. The whole unit is sleek and lightweight — the black surface is smooth and won’t become an eyesore. It blends perfectly with the RV decor.

The tankless boiler is also compact. It measures 11 inches by 7.5 inches by 2.35 inches and weighs roughly five pounds. There’s no bulky tank sitting in your RV promoting bacterial growth or rusting issues.

Features Touch Panel and Remote Control

On the smooth black surface, you have the touch control panel. This panel enables you to get the exact temperature setting. It takes the guesswork out of having to turn a dial and cross your fingers that you aimed right.

Another reason why we chose the black model is that it comes with a remote control. What’s amazing and super convenient about this is that you can mount the remote on the wall above your sink. From here, you can quickly adjust the temperature for your needs.

Easy Installation

The installation of this unit is pretty straightforward. In fact, Ecotouch advertises that you can do it all yourself without the help of a plumber. For the installation, you’ll get a 0.5-inch NPT pipe fitting, brackets, and a 12 AWG power cord already attached.

The unit is meant as a point-of-use water heater, meaning that you install it where you’ll need it. But what makes the installation more convenient is the 360-degree option. You can mount it vertically, horizontally, or diagonally — how it fits best for you — without compromising functionality.

Smart Modulation Technology

The unit features smart modulation technology which not only saves energy but also prevents scalding water.

The intelligent technology enables the unit to calculate its required power input and adjust accordingly. So, if you’re reducing water flow while washing hands, the boiler reduces its power input to avoid scalding water.

This self-adjustment minimizes energy waste. Thanks to this feature, the unit can achieve up to 65 percent in energy savings. Ideal when you don’t want to waste a lot of money heating water during your holiday.

Keep In Mind

Not Ideal for Showering

Ecotouch warns that their tankless boiler works best as an under sink water heater. It produces about a gallon of hot water per minute, which may not be ideal for taking a shower.

Additional Specs

Measurements 11 inches by 7.5 inches by 2.35 inches
Flow rate 1 gallon to 1.5 gallons per minute
Temperature range 67 to 109 degrees Fahrenheit
Weight 5.7 pounds
Warranty N/A

5. Eemax EEM24018 Electric Tankless Water Heater

Best Aesthetically Pleasing Tankless Water Heater Unit

From an aesthetic point of view, this product delivers. It’s metallic blue and features a digital thermostat — easy to read and use.

With that said, we didn’t just pick this tankless water heater because of its appearance. It’s also energy efficient while supplying a large amount of hot water. Similar to some of the products above, it features a self-modulating technology.

It adjusts according to need — eliminating the risk of wasting excessive energy. Eemax claims that the unit can provide enough hot water for a sink and shower running simultaneously. However, some users noted that it doesn’t perform as advertised, so you’ll have to choose between a shower or doing the dishes.

Why We Love It

Beautiful Design

The unit looks very appealing with its metallic blue color and sleek digital thermostat. It displays the exact temperature and you can choose between “high” and “low.” The unit is also quite compact in size which saves a lot of valuable space inside your RV.

Prevents Excessive Energy Waste

The Eemax heater also comes with advanced self-modulating technology. Much like other products on our list — it will adjust how much power it draws depending on your usage. In turn, saving energy and water.


Measuring 17  by 14  by 3.75 inches, this water heater is a real space saver.

Keep In Mind

Doesn’t Perform as Advertised

Eemax claims that the unit can provide enough hot water for a sink and shower running simultaneously. However, users were quick to say that it barely held up for a hot 8-minute shower.

Additional Specs

Measurements 17 inches by 14 inches by 3.75 inches
Flow rate 2.3 gallons per minute
Temperature range 80 to 140 degrees Fahrenheit
Weight 14.47 pounds
Warranty Five-year warranty on leaks, one year on parts

Rv Tankless Water Heater Comparison Chart

Product Award Measurements Weight (lbs) Temp. Range (F) Flow rate (GPM) Warranty
EcoSmart 8 KW Best For Eco-Friendly Camping 11.5″ x 8″ x 3.75″ 5.3 80 – 140 1.5 Limited lifetime
Stiebel Eltron 12 Best For Larger RVs 14.5″ x 16.2″ x 4.5″ 13.5 86 – 140 1.3 – 2.5 7 years
Camplux 2.64 GPM Best For Off-Grid Camping 12.8″ x 6.1″ x 21.65″ 18 N/A 2.64 N/A
EcoTouch Best For High-Tech RVers 11″ x 7.5″ x 2.35″ 5.7 67 – 109 1 – 1.5 N/A
Eemax EEM24018 Best Aesthetically Pleasing 17″ x 14″ x 3.75″ 11.25 80 – 140 2.3 5-year on leaks, 1 year on parts

Questions and Answers

How Should I Install a Tankless Heater in My RV?

Before installing the unit, figure out where it should be located. Once you’ve found the right spot, you will most likely have to mount the unit to a wall or the floor. You will then have to connect gas or electricity lines (depends on your boiler) to power the unit.

If you have a gas powered water heater, you will also have to install a flue. The flue pipe will direct and discharge the fumes and combustion created by the gas. It’s essential that the flue pipe rises upward for the gases to successfully exit the heater (3).

It’s crucial to get rid of these gases since they contain toxic carbon monoxide. If the fumes are leaking out into your RV, it could be fatal (4).

Lastly, it’s time to connect the boiler to the onboard water tank. Grab the inlet and outlet pipes and connect them to the unit. Follow your user’s manual for exact locations.

If you have any doubts about installing the unit properly, we highly suggest you seek professional help.

Can I Install a Tankless Heater Underneath an RV Sink?

Yes, you can. And, having the tankless heater closer to the faucet actually comes with several benefits if you do. For one, it means you won’t have to wait as long for the hot water to arrive.

Most tankless heaters are easy to install underneath a sink. There’s no need for complicated wiring or tools only a plumber has. However, before you purchase a heater for your sink, make sure it will fit so that you don’t run into difficulties.

Let’s Hit the Road

A tankless water heater is an excellent choice for an RV. Most are electrical and can provide hot water exactly where you need it. Because they’re tankless, you haven’t got a bulky tank taking up valuable space inside your vehicle.

Which was your favorite unit that you’d like to bring onboard? Please leave us your reply below, or share your experience with these heaters in your RV.

Headshot of Peter Gray

About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.