Best Outdoor Tankless Water Heaters of 2021 – Complete Review

| Last Updated: September 22, 2021

It is no less than trauma to wash your face or even take a bath with freezing cold water in winters.

A water heater is a must! So if you are renovating and looking for the best heater to install in your new house, you have come to the right place.

Keep reading to lean more about tankless water heaters for outdoor use and what to look for when buying one.

Comparison Chart of the Best Outdoor Tankless Water Heaters

IMAGEPRODUCT
  • Highly portable tankless water heater
  • Works perfectly with 12V 1.2 GPM water pump
  • The maximum temperature is 46 degree Celsius, and the minimum is 6 degree Celsius
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  • Works on natural gas with easy installation
  • Has up to 6.5 GPM hot water rate
  • Control 2.0 mobile features
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  • Best for the money
  • Lightweight with a very portable design
  • Fully adjustable heat and water flow
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  • Best outdoor propane tankless water heater
  • Offers thermal efficiency of 88.5%
  • Maximum power output is around 110,000BTU per hour
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  • Best outdoor electric water heater
  • Activation flow is around 0.3 GPM
  • Equipped with copper and stainless components
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Can Any Tankless Water Heater Be Kept Outdoors?

No, not all tankless water heaters are suitable for placing outdoors. Usually, when you decide to buy a new heater, you have to pay attention to which option is better for you: an outdoor or an indoor heater. An indoor heater is suitable to be placed indoors, whereas an outdoor heater can be easily placed outside.

If your house is under construction, it is wise to install an indoor tankless water heater. On the other hand, if your house is already constructed and you recently became aware of your need for an additional heater, then an outdoor heater would be a suitable option. 

Photo credit: eccotemp.com

How to Choose an Outdoor Tankless Water Heater

There’s no rocket science in choosing the right tankless water heater. All you have to do is keep the following points in mind:

Capacity

The first factor that needs your attention is capacity. How much area needs to be covered? If you wish to supply warm water to around six washrooms, then a standard tankless water heater won’t be enough for you. So, in that case, you need a heater that’s larger in size or capacity. 

Price

Your budget will help you narrow down your options easily. Most standard heaters cost around one thousand dollars. So it will be better if you narrow down your options depending on your budget.

Warranty

Another option that you need to be careful about is the warranty. Which is a better option, something with a warranty or something without a warranty? Consider a tankless water heater that comes with the warranty of at least a couple of years as your best option. It is always wise to have a warranty as far as technical pieces are concerned. You never know when something will stop working. Having a free repair service might come in handy.

Compatibility

Compatibility means that you need to make sure your new heater fits perfectly with the pipes of your house. Minimize your expenses and limit the expenditures as much as you can. 

Review of the Best Outdoor Tankless Water Heaters

We have made a list of the very best tankless water heaters on the market. So, go through the pros, cons, and main features of these heaters and choose the very best one for your house, restaurant, or office.

Best Overall

Camplux 5L 1.32 GPM Outdoor Propane Tankless Water Heater

Camplux 5L 1.32 GPM Outdoor Portable Propane Tankless Water Heater,Black

Specifications

Max Water Flow (GPM): 1.32

Energy Factor (EF): N/A

Dimensions: 14.8 x 11.42 x 4.33 inches

Water Temp Range: Low 46.4 -High 114.8

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What Recent Buyers Report

Most recent buyers of this tankless water heater are happy with its performance. One of the recent buyers reported that since it comes with every must-have feature, it is the best overall heater. Another buyer said that operating it is a piece of cake and he did not have any trouble at all.

Why it Stands Out to Us

This tankless heater is portable, so that makes it stand out to us. It is beautifully designed, keeping in mind portability, energy-saving, and innovation. So take advantage of these key features by purchasing this heater. In addition to this, it saves a lot of money and is very compact.

Who Will Use This Most

If you are a camper in desperate need of a portable unit, you would really enjoy it. You can easily move around this unit. If you need hot water to wash your horse, car, or even your boat, this portable outdoor tankless water heater has you covered.

Bottom Line

Lastly, invest in this remarkable propane tankless water heater and take advantage of its never-ending benefits. From the ideal pressure range to multiple protective features, this tankless water heater has everything. So if you think you can benefit from its features, then invest in it and say goodbye to freezing cold water.

Pros

Compact size holds loads of water

Lowest water pressure starts at 2.5 PS

Comes with anti-freezing protection features

Features oxygen depletion shut-off protection

The output is of 1.32 gallons per minute of hot water

Cons

Have to be careful with propane

Runner-up

Rinnai V Series HE Tankless Hot Water Heater

Rinnai V65EN RV65eN, Large, White

Specifications

Max Water Flow (GPM): 6.6

Energy Factor (EF): 0.82

Dimensions: 9.6 x 14 x 24.3 inches

Water Temp Range: Low 98 -High 140

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What Recent Buyers Report

Almost everyone that has invested in this unit is extremely happy with the outcome. One of the recent buyers said he couldn’t believe how small it was! He further reported that he is extremely satisfied with the hardware, gas lines, wire lines, and overall performance of this heater.

Why it Stands Out to Us

The very reason this heater is affordable and efficient makes it stand out to us. It is efficiently packaged in a compact design and is designed in a way that makes it energy and user-friendly. It uses 40% less energy than traditional tanks because it only offers heated water right when you need it.

Who Will Use This Most

If you are looking for hot water on demand from a tankless heater that does not take a lot of your space, this is the very best option. These water heaters are built on the ThermaCirca360 technology that easily circulates hot water through pipes.

Bottom Line

This unit provides endless hot water on demand, saves valuable space, sustains reliability, is backed by 100 years of user confidence, and is very affordable and efficient. So stop overthinking and start saving up some money to invest in this beautiful and efficient heater.

Pros

Consumes 40% less energy

Comes with residential factory warranty

Equipped with smart technological advancements

Easy to install and saves valuable space in your house

Provides an endless supply of hot water for the entire home

Cons

Water pressure is low in some settings

Con3

Best for the Money

GASLAND Outdoors Tankless Water Heater

Tankless Water Heater, GASLAND Outdoors BE158 1.58GPM 6L Outdoor Portable Gas Water Heater, Propane Water Heater, Overheating Protection, Easy to Install, Use for RV Cabin Barn Camping Boat, White

Specifications

Max Water Flow (GPM): 1.58

Energy Factor (EF): N/A

Dimensions: 11.8 x 6.1 x 17.3 inches

Water Temp Range: N/A

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What Recent Buyers Report

One of the recent buyers reported that when he was renovating his house, he needed a tankless heater that was easy to install and did not take much space. Keeping these things in mind, this unit seemed to be the perfect option. He was happy with the ability to get warm water in the shower. Overall, all users were satisfied with it.

Why it Stands Out to Us

Its multiple protection and safety features are the reason it stands out to us. To ensure your safety and the safety of your family, this heater comes with a flame failure device, anti-freeze protection, and overheating protection. It even comes with an anti-freezing drain plug that discharges any residual water to avoid freezing.

Who Will Use This Most

If you have kids in your family, then you will appreciate the benefits of its multiple safety and protection benefits. If your child has mistakenly turned it on and forgotten to turn it off, a feature is present to shut off the gas automatically and save you from danger.

Bottom Line

This heater offers an endless list of features, so what is stopping you from buying this one? You don’t even have to spend a couple of thousand dollars on this one, as it does not come with a heavy price tag attached to it. Have access to around-the-clock hot water with this tankless heater.

Pros

Not that heavy on your pocket

Maximum power output is 41,000BTU/Hr

Build with 11.5% energy-saving technology

Turns off the heater in case of an emergency

Very easy to install, while keeping instructions in mind

Cons

Might have some problems with the hose

Best Outdoor Propane Tankless Water Heater

Camplux 16L Outdoor 4.22 GPM Propane Tankless Water Heater

Camplux 16L Outdoor 4.22 GPM Digital Display Propane Gas Tankless Water Heater

Specifications

Max Water Flow (GPM): 4.22

Energy Factor (EF): N/A

Dimensions: 17.32 x 7.87 x 27.56 inches

Water Temp Range: N/A

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What Recent Buyers Report

Most of the people who have this heater installed in their homes are very satisfied with its performance. One of the recent buyers reported that he gave this as a gift to her boyfriend, and he was over the moon. The other one reported that it is very easy to install and mount, making it one of the very best.

Why it Stands Out to Us

This heater, specifically, stands out to us for many reasons. One of those many reasons is the fact that it is portable. You can carry it anywhere you want, and you can even take it to places where there’s no electricity, as it comes with 2D batteries, and those batteries tend to last a very long time.

Who Will Use This Most

If you are looking for a heater for camping or your cabin, or even if you want a steady supply of hot water when bathing your pets or car, a portable tankless water heater can come in handy. So if you fall into any of the above-mentioned categories, then it is about time you consider this heater.

Bottom Line

Lastly, these types of heaters are perfect for an outdoor shower, bathing horses, and washing pets. Plus, it even comes with temperature control sensors, which makes it very easy to monitor the temperature regulations. So if you are looking for a heater to buy, it is important to invest in this system.

Pros

Easy to fix and install

Has a digital temperature display

Comes with a quality rubber/plastic water hose

A limitless supply of hot water anywhere, anytime

PFeatures a simple design and high output structure

Cons

Sometimes the off and on button might act up

Best Outdoor Electric Water Heater

EcoSmart ECO 27

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

Specifications

Max Water Flow (GPM): 6.5

Energy Factor (EF): N/A

Dimensions: 17″ x 17″ x 3.6″

Water Temp Range: N/A

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What Recent Buyers Report

One of the recent buyers of this efficient and economical tankless water heater claimed to be very satisfied with its performance. It allowed him to control some of the main features and to customize it depending on their needs. Plus, another buyer was excited about its limited lifetime warranty feature.

Why it Stands Out to Us

It stands out to us because it offers a constant supply of heated water. Plus, how can we forget to mention its warranty? This heater is made of well-crafted components. Even if one of those components stops working, you can easily find its replacement in the market. In addition to this, this heater help its users save electricity and power.

Who Will Use This Most

If you belong to the group of people who find it hard to survive without warm water and need instant access to warm water as well, this outdoor electric tankless heater would be a perfect fit for you. Moreover, if you like to customize and play around with features, then do consider this an option.

Bottom Line

Pay attention to its capacity, pipe size, weight, material, build, and other important factors, and then reach your final conclusion. For standard daily use, this is one of the very best heaters out there on the market. We are certain you won’t be disappointed with its features.

Pros

Comes with a limited lifetime warranty

Very easy to install and mount on the wall

Beautiful design offers more storage space

Has easily replaceable items and components

Most advanced and self-modulating technology

Cons

The warranty comes with certain terms and conditions

Best Takagi Outdoor Tankless Water Heater

Takagi T-K4-OS-NG

Takagi T-K4-OS-NG Tankless Water Heater, Natural Gas, Outdoor

Specifications

Max Water Flow (GPM): 8

Energy Factor (EF): N/A

Dimensions: 8.5 x 13.8 x 20.3 inches

Water Temp Range: N/A

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What Recent Buyers Report

Most recent buyers of this tankless water heater are extremely happy with its performance and how it offers on-demand heated water instantly. One of its recent buyers reported that this is the quietest and safest heater he has come across. One even called it a Japanese miracle of the 21st century.

Why it Stands Out to Us

It comes with a 15-year limited heat exchanger and five-year limited for residential use, which gives more control to the user. In addition, this also includes a temperature controller as a standard feature. So instead of going outside, the user can increase or decrease the temperature while sitting inside.

Who Will Use This Most

If you are looking for a tankless heater that is easy to install and does not startle you from your slumber, then this is the very heater that can satisfy all of your needs. Moreover, it is easily affordable as well, so consider this as one of your potential options.

Bottom Line

With a remarkable flow rate of 8 GPM and a copper heat exchanger, it is one of the best tankless water heaters on our list. Plus, it saves its user from extra trouble since it comes with a complementary recess box, pipe cover, remote temperature controller, and even lead-free isolation valves and pressure relief valve. Investing in this is a wise option.

Pros

No need to install a vent pipe

Comes with a 5-year heat exchanger

Easy to install, so you don’t need a pro 

Yearly heating bill goes down to a certain degree

Usually placed outside, so it saves loads of space

Cons

Warranty is not applicable to all parts

Best Noritz Outdoor Tankless Water Heater

Noritz NR50ODNG

Noritz NR50ODNG Outdoor Tankless Water Heater, max. 120,000 Btuh, 5.0 Gpm - Natural Gas

Specifications

Max Water Flow (GPM): 5

Energy Factor (EF): N/A

Dimensions: 10.7 x 17.6 x 26.6 inches

Water Temp Range: N/A

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What Recent Buyers Report

Most recent buyers of this Noritz heater are satisfied with its installation process. Another one of its recent buyers reported that he was looking for a replacement of his old heater because that model was prone to leaks. On investing in this unit, he is very satisfied with its efficiency and high performance. The same was reported by other users, as well.

Why it Stands Out to Us

The very fact that this outdoor tankless water heater is lightweight and easy to install makes it stand out for us. It saves you from a call to a professional to come install this heater and charge extra for it. So install it by yourself and save those extra charges.

Who Will Use This Most

Those who need a tankless heater but don’t want to spend a huge amount of money installing and fixing it would be glad to know that this unit is just a piece of cake. All you need is a tiny space, a couple of tools, and rest is all figured out.

Bottom Line

Highly efficient, highly economical, easy to install, and with multiple safety features, all these are a deal-breaker. So if you are often away from your house but are not sure how much hot water you need, this is a perfect choice, for you would quickly be able to access heated water once you are back from your trip.

Pros

Compact in design

Features low NOx technology

Easily affordable by most users

Only weighs 33 pounds, making it easy to lift

Comes with 12-year heat exchanger, 5-year parts, 1-year labor warranty

Cons

Not ideal for six showers

Best Rheem Outdoor Tankless Water Heater

Rheem RTG-84XLN-1

Rheem RTG-84XLN-1 Performance Mid-Efficiency Tankless 84 Outdoor Water Heater, Gray

Specifications

Max Water Flow (GPM): N/A

Energy Factor (EF): N/A

Dimensions: 8.88 x 13.88 x 23.63 inches

Water Temp Range: N/A

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What Recent Buyers Report

One of the recent buyers reported that his last water heater lasted for roughly seven years, and after evaluating this one’s performance, he concluded this one would last even longer. Another recent buyer reported that he is quite impressed with the quality of this heater, as it does justice to its price. In fact, nearly all the users were satisfied with its performance.

Why it Stands Out to Us

It stands out to us because of its intelligent electric controls that are designed especially to increase efficiency and safety. Plus, it comes with a remarkable display screen that keeps its users informed of temperature and maintenance settings. This heater is also environment-friendly, so all of these factors are what makes it extra special.

Who Will Use This Most

People who are looking for a new heater with a couple of important safety features, a display screen to monitor temperature, a reliable body to resist harsh weather conditions, and a couple of other important features should really consider this model. It provides a constant and consistent supply of hot water.

Bottom Line

The self-diagnostic system, water-saving mode, maintenance mode, next-generation burner technology, and long, never-ending list of countless other features make this outdoor tankless water heater an ideal choice for its users. If you want to update your current heating system, this is a perfect choice.

Pros

Easy to install, even for an amateur

Features remote control terminal block

Reliable, secure, efficient, and very compact

Comes with a replacement screw and O-ring kit

Finishing and material are made of stainless steel

Cons

Is a bit heavy when it comes to the weight

Aspects to Consider Before Buying

Whenever you are thinking about getting a new heater, there are some things you must consider before making a final decision. The following are some of those factors that can help you in making a decision regarding a tankless heater.

Reliability

The first thing that needs your attention is reliability. If the item you are purchasing is not reliable, then it’s a waste of money. One can’t invest in a new water heater every winter. Heaters are a one-time investment. If you don’t mess with their pipes, they tend to last a long time. So check all the features before handing over the money to your retailer.

Camplux 5L 1.32 GPM Outdoor Propane Tankless Water Heater

Material

It is better if we pay attention to the material of the heater, as it will be exposed to harsh weather conditions. Of course, you don’t want it to rust in the rain. So a heater with a durable make would be an ideal option. 

Features

Make sure you are getting what you paid for. Does the heater have all the features that it promises? Tally all the main features listed on the box with all the features it exhibits, and you will have an idea regarding the standing of your heater.

Conclusion

Now that the main features and pros and cons of the very best heaters in the market are in front of you, we are certain you have the tools to make a wise decision. Choose the one with higher BTUs and one that’s extra efficient and extremely easy to install and move around.

People Also Ask

Here we have answered some of the most important and frequently asked questions regarding outdoor tankless water heaters. Go through them, and we are hopeful you’ll be able to get rid of any confusion related to outdoor tankless water heaters. 

How Do I Keep My Tankless Water Heater From Freezing Outside?

Follow these steps to keep your tankless water heater from freezing outside:

1. Install your heater in a warm place.

2. Drain your old water heater.

3. Always maintain a stable connection source.

4. Pay attention to the recirculation system.

5. Always insulate all the fittings.

6. Lastly, running a trickle of water will really help.

How Do You Winterize a Tankless Water Heater?

The process of winterizing your tankless water heater is extremely easy. All you have to do is:

1. Turn off the water heater.

2. Unplug the power cord.

3. Disconnect or shut off the water and gas supply.

4. Open the hot water source to drain the water.

5. Lower the water pressure.

6. Cut off the connection between the outlet and inlet water pipes.

Do Tankless Water Heaters Run Out of Hot Water?

Technically, a tankless water heater can’t run out of hot water. This does not mean it does not exhaust itself when demand is high. So if more than two taps or showers are demanding hot water at the same time, then the heater has to drain some extra power to make everything run smoothly. 

How Long Do Tankless Water Heaters Last?

If a tankless water heater is used in the correct way, then it has a life expectancy of two decades that makes it twenty years. One of the reasons is also that the spare parts of these sorts of heaters are easily available, so if something breaks down, it can easily be fixed.

What Size Breaker Do I Need For a Tankless Water Heater?

The ideal nature of the breaker is mentioned in a tankless water heater. Usually, an outdoor tankless water heater requires a 40 to 50-amp breaker for each wire. Each wire is responsible for supplying to one element, and ideally, it requires three breakers ranging from 40-50 amps. 

How Often Do You Need to Descale a Tankless Water Heater?

You need to descale a tankless heater once a year. But in case you live in a place where only hard water is available, and you keep the temperature at the maximum at all times, you need to descale your heater at least once every six months. 



My name is Bob Wells and I am a retired HVAC tech from Washington state. I am currently retired and no longer do much with HVAC, however, I feel like I have a lot of knowledge in the subject and I wanted to create a website where I could talk about what I've learned and help upcoming HVAC techs. Find more info about me and HVAC Training 101.