TanklessWaterHeaterExpress is reader-supported. As an Amazon Associate I earn from qualifying purchases.

7 Best Outdoor Tankless Water Heater Reviews in 2021 [Buying Guide Inside]

It can get too long to heat 40 gallons of water and then take a shower. If you are staying under extreme conditions, the time taken is almost double. This is mainly because it first has to defrost the stored water and then heat it again. If you are travelling with 4-5 people, it may take almost 2 hours to complete the bath. Who would like to spend so much time when it comes to getting yourself ready and moving onto the next destination?

The solution is simple… get an outdoor hot water heater that will do your job in a few minutes. The main work function of the outdoor tankless heater is to adapt to the conditions and then heat the water. Since it is tankless, it provides instant hot water and endless flow. So you won’t have to wait for long hours of hot water at all. Since they are light in weight, it’s easier to carry them and install on the go.

However, the most daunting task in hand is to pick up the right product. Not every outdoor tankless water heater that you see will be able to satisfy the requirements. There are a lot of specifications and research that needs to be done. Of course, you are at the right place to find the best outdoor tankless heater available. Look down below to find out complete reviews and also a buying guide.

1. GASLAND Outdoors BE158 Heater – Best Overall

When I got my hands on this heater, it immediately caught my attention because of the lightweight and portable design. As an outdoor tankless heater, I would have expected it to be light and compact. However, BE158 is just what I was looking for.

This heater comes with an overall weight of 15 Pounds which became easier to carry. It is just 11 inches wide and 17 inches tall. So installing or lifting the BE158 was never an issue at all. It’s fair to say that this product has impressed me the most because of such features.

Why is it Unique

How many heaters can provide an instant heating boost even in extreme weather. However, the BE158 has impressed me the most because of this. It comes with a maximum power output of 41000 BTU per hour to provide endless hot water. Even while I tested the product at a higher altitude, I felt that it has the best productivity for instant heating.

The overall buildup of the BE158 is created in such a way to deliver you with a lightweight structure. As a result, it also requires lower force to start heating, Comparing with the other models, you can easily find that the BE158 can easily save up to 11.5% of electricity bills on the go. To help to reduce the bills, GASLAND has introduced advanced combustion technology.

Buyer’s Experiences

One of the consumers on Amazon has quoted by saying “Works great.” He referred to the working condition of the BE158 heater and it seemed to be quite helpful. According to him, finishing up the configuration and then installing the product was easy. As a result, it took just 10 minutes to set up the heater while camping outdoors.

Best Fit For

The BE158 features anti-freezing protection that will allow you to instantly defrost the water running through the pipe. As a result, you can always get faster productivity when it comes to heating the water. But the most impressive feature is the CSA approved safety. This model includes all the advanced safety features which keep the BE158 safe from any type of gas leaks.


Comes with an installation guide
This product is easy to install
It has a compact and light-weight body
Electricity consumption is low
Comes with a 1-year warranty with the product


No batteries are present

2. Rinnai V53DeP Tankless Water Heater – Best Performance

When it comes to the performance, the Rinnai V53DeP is something that has amazed me the most. Of course, when any heater delivers you at a rate of 5.3 gallons per minute, you would want to carry it everywhere.

The Rinnai V53DeP is one such product that will amaze you. I have checked the workflow rate for the Rinnai V53DePat different temperature levels of the groundwater and all of them seemed to work perfectly. Needless to say, I had to store this product as a top purchase for everyone willing to go by performance.

Why is it Unique

The Rinnai V53DeP features a Control-R application to allow you to alter the settings. With the help of this mobile application, you can easily set the times, make schedules throughout the day and even you can get the ideal system. This will allow you to put the system to the vacation mode and keep it off until you complete the vacation and then result back home.

Another impressive feature is the on-demand hot water from the Rinnai V53DeP. To bring this to an effect, Rinnai uses the ThernaCirc360 technology that allows you to recirculate the hot water faster and better. Because of this, it can provide you with an endless source of hot water. With this feature, you will never run out of hot water but you need to change the filter and use it.

Buyer’s Experiences

One of the consumers on Amazon has claimed that “Very good folks. I couldn’t believe how small this unit was!” According to the owner, it is by far one of the smallest models introduced by the manufacturers to get the right productivity. To be fair, this product features a great hardware component and also includes all the safety features to make it count. Rinnai V553DeP is a great product to have.

Best Fit For

The Rinnai V53DeP seems to be a compact product that takes up very less space to fit in. This product comes with a squeezed design and a perfect shape. This will allow you to easily install the heater in small spaces like an attic or even in a closet. It seems to be a complete professional when it comes to performance and also the shape. You can save up a lot of space for installing this product.


Comes with endless hot water
It has high-efficiency ratings
The product is light in weight
10 Years warranty on the heat exchanger
It features a high water flow rate


The price is a bit high

3. EcoSmart ECO 11 Tankless Water Heater – Best Budget

We all know about how competitive this brand is right from when it was launched. The EcoSmart ECO 11 is one such product that has amazed me the most not only because of the performance but also for the small budget category that it falls under.

Even when I compared the EcoSmart ECO 11 with other products of the same budget, none of them was able to provide me with the ultimate comfort while heating and also in a quick period. But what impressed me the most is the 60% energy and budget save while running this product. This allowed me to enjoy the services better.

Why is it Unique

The EcoSmart ECO 11 comes with a high energy efficiency rate. To be precise, it resembles almost 99.8 % energy efficiency. As a result, you can always expect this product to deliver you top-quality heating without the loss of much energy. The conversion rate is good and this is the reason why it has a high uniform energy factor of 0.98. You can expect the heating coil to deliver you a better performance.

This product comes with an easy heating mechanism that prevents heat loss and also water loss at the same time. It performs with the self-modulating technology that can instantly heat the water without even storing it. Because of this, it acts as a smart tankless water heater which is best suited for our outdoor activities providing you with comfort.

Buyer’s Experiences

One of the consumers on Amazon said: “So far I am very happy with this unit”. The owner purchased this heater back in 2017 and it seemed to be quite satisfying for him. Till today he has not faced any such problems and it has delivered a good performance.

Best Fit For

The EcoSmart ECO 11 features an easy heat temperature dial knob at the front panel. It has a specific thermostat at the front that will allow you to alter the temperature accordingly and then you will be able to choose or preset the temperature. Moreover, the temperature control is digital and it shows you the current settings. All the spare parts are easily replaceable and you can get good support from EcoSmart.


Comes in a small size
It can reduce more than 60% energy
It has a lifetime warranty feature option
Includes Self Modulating Technology for heating
You can get endless hot water


Not great for extreme cold weather

4. Rinnai V65EP Tankless Water Heater – Best Outdoor Propane Tankless Water Heater

The Rinnai V65EP is another impressive product from the manufacturer that has brought up the limelight in design and installation. The product features a compact design that is built to save space. When you are carrying the Rinnai V65EP for a long outdoor trip, it will be much easier to carry this product because of the lower weight and the space that it takes.

All that you need to do is to select an appropriate location and the installation will be done in just a few minutes. Coming to the performance, it has a propane fuel injection system to heat up the water better.

Why is it Unique

The Rinnai V65EP comes with a durable heat exchanger that has high efficiency. Since it consumes propane fuel, it can lower the levels of electricity consumption and provide you with ultimate results. To be fair, you can get almost 10 years of warranty with the product. If you ever face any problem with the heat exchanger, the Rinnai team is just one step away.

Another impressive feature about this outdoor propane heater is the high flow rate of the heater. It comes with a decent 6.5 gallons per minute production. Not many products with such compact size can provide higher levels of productivity and water flow rate like the Rinnai V65EP.

Buyer’s Experiences

One of the consumers on Amazon said “Very good replacement for tanks on a 2 bed 1 bath rental home.” The user had earlier purchased several other tank-based models but they fairly did not impress him. However, the compact body and extreme hardware support are always reliable. The user has always been impressed with the features that the Rinnai V65EP has.

Best Fit For

The Rinnai V65EP comes with self-modulating technology that uses the flow of water to heat up. As a result, you can get endless hot water to get the best results. At the same time, it has a Control-R application that will allow you to get the best settings and control features. With just a single click you can alter the temperature and set timers that will help you to get the right result.


Comes with a high-efficiency heater
This product features low NOx emissions
Comes with inbuilt safety features
No venting installations needed at all
It performs well at higher altitude


Not for big requirements

5. Ecosmart ECO 18 Electric Tankless Hot Water Heater – Best Outdoor Electric Tankless Water Heater For Camping

When you go out for a trip to camping, you would need a heater that becomes easy to carry and also has a simple setup procedure. The Ecosmart ECO 18 is exactly what you were looking forward to having in your home because of the easy to use options.

When I tested this product, it took me a maximum of 10 minutes to complete the installation and then keep using the heater for endless hours. But you must remember that a warranty will be void if you do not install it by a professional. However, everything happens without any much interruption.

Why is it Unique

The Ecosmart ECO 18 comes with high-quality materials for the buildup. All the internal components are properly constructed that provides you with top-notch quality and material. Precisely, this product comes with copper and stainless components that will deliver you with proper results. Because of the copper material, it becomes much easier to heat the water.

The Ecosmart ECO 18 comes with new self-modulating technology. This technology is designed to save up the energy and be efficient with this. As a result, you can expect this product to deliver you quick hot water without wasting much energy. Overall, Ecosmart guarantees you to save up to 60% on the water heating costs.

Buyer’s Experiences

One often consumers on Amazon quoted by saying “Excellent Product, Unmatched Quality at a very reasonable price”. This review was posted exactly after one year of purchase from the manufacturer. The user has come up with complete satisfaction that has helped his commercial store requirements. To be fair, it’s one of the best devices for them to use for a long time. However, it can be a good result for camping

Best Fit For

This product comes with a small size and you will also get a digital temperature control. There’s a dial knob right at the front panel that will allow you to adjust the temperature according to the needs. It has 1-degree increments which you can easily alter according to the requirements that you have. This will help you to accurately heat the water for colder climates.


Construction and internal parts are good
It features self-modulating technology
Lifetime warranty for residential use
Copper and stainless components
It is easy to use and to install


Flow is not the best

6. Rinnai V65eN Outdoor Natural Gas Tankless Water Heater – Best For Low Energy

Not many tankless heaters can be so reliable just like the Rinnai V65eN. Coming from a great background, this heater is designed to provide you with ultimate comfort and reliability. To be fair, it has a proper energy-efficient mechanism that allows the heater to save up water and also consume less energy.

Compared to the other products, you can expect this model to work with 40% less energy and work better. The maximum energy rating factor for the product is around 0.82 which makes it much more reliable to use.

Why is it Unique

This product features instant hot water on demand that will deliver you a constant solution to your problems. But the one factor that impressed me the most is the ThermaCric360 technology that will give you a proper result. This technology has been introduced by Rinnai to cut down the costs of energy and bring up the levels of supply.

Another impressive feature of the Rinnai V65eN is the compact design and space-saving concept. Merely, this heater weighs around 47 pounds and this is the reason why it becomes easy to carry. Since it is compact in design, it also takes very less time to heat the entire unit. To be precise, the unit heats up at a rate of 120000 BTUs which makes it lightweight and compact.

Buyer’s Experiences

One of the consumers on Amazon commented as “Super Energy Efficient”. He refers to the Rinnai V65eN which becomes highly efficient for most of the people to work under extreme temperatures. The temperature control mode could have been a bit better, but it still does great work. The overall Control-R application is decent for anyone to use.

Best Fit For

One of the reasons why most of the people love this outdoor gas water heater is because it has low NOx emissions. It has been tested in various labs and you can assume this product to be fair for high-efficiency delivery and up to 6.6 Gallons per minute. This rate of delivery is sufficient for delivering a massive rate of hot water even under extreme temperatures. The low energy consumption acts as a bonus.


It can provide you with endless hot water
The product can save up valuable space
It is capable of Circ-Logic
Comes with on-demand hot water
You can get Control-R application


It’s not the best for hard water

7. Eccotemp L5 Portable Outdoor Tankless Water Heater – Best For Installation

If you are ever looking for a product that will serve you while you are travelling, the Eccotemp L5 is the one. This product has been completely developed and designed in the USA providing the people with utmost comfort.

You can always expect it to deliver you with proper results. Unlike a big sized heater, the Eccotemp L5 looks more like a small and box heater. It has all the basic standard safety features that you would love to have in your trip and quickly set up the product.

Why is it Unique

The Eccotemp L5 comes with a constant Propane fuel injection. Because of the liquid propane fuel, it consumes very less gas. To improve the heating cycle, it has specialized features that help in reducing the NOx emissions and bringing the heater to effectiveness. To promote the work, the Eccotemp L5 comes with 2-D cell batteries so that you do not require electricity.

Another impressive feature of the Eccotemp L5 is the CSA regulator. It has two adjustable knobs that allow you to alter the settings. One of them is the thermostat to control the temperature. However, the other knob is present to allow you to control the rate of flow. You can alter both of them to work according to your preference.

Buyer’s Experiences

One of the consumers on Amazon said: “The heater is nice to have”. The user purchased the heater back in 2018 and it has been almost two years he is using this. He has generally purchased the Eccotemp L5 to replace the old 5-gallon tank based heater and it seems that he is completely satisfied. A 10-minute complete installation just made it easier to start using the heater.

Best Fit For

The Eccotemp L5 has simple components and spare parts for the products. As a result, it always becomes easier to install the product in a jiffy. You can simply have a look into the DIY guide that is present with the product and you can easily install the heater while viewing it. But the one thing that impressed me the most is the 24 x 7 customer support from Eccotemp.


It is lightweight and portable
Easy to setup options
Comes with manual temperature controls
You can get battery-operated usage
Comes with manual temperature controls


Not for massive continuous output

Editor’s Pick

Choosing a tankless heater for your outdoor needs is always a difficult task in hand. There are so many products already available in the market today and it becomes a difficult choice to pick up the best product out of all. If you are running out of time and in a hurry, you can simply have a look into this Editor’s pick section where you will be able to find the right match for you. Below, you will find a comparison for the top3 picks that I have mentioned.

The GASLAND Outdoors BE158 Heater is my pick as the best overall product available. It is completely light in weight around 15 pounds which makes it easier to install outdoors. Some of the other features for this product include 41000 BTU per hour that can provide you with endless running hot water. As a result, you can always expect the product to deliver you with instant heating options.

The Rinnai V53DeP Tankless Water Heater is my choice as the premium pick product. It is the best when it comes to performance and controls. To heat the water, it uses the ThermaCirc360 technology that allows you to get instant heating. On the other hand, the Rinnai V53DeP Tankless Water Heater features a Control-R WiFi module that allows you to adjust the temperatures remotely.

The EcoSmart ECO 11 Tankless Water Heater is the best budget pick amongst all the tankless water heater outdoor available. At this price bar, having a product that saves 60% of energy is a rare catch. To be specific, this product comes with a 99.8% energy efficiency which is the highest in its class. It also has a 0.98 energy factor which is responsible to save up money while using the product.

Buying Guide – Choosing the Right Outdoor Tankless Water Heater

When you wish to buy the best tankless water heater according to your needs, there are a few factors which you need to consider as a primary result before choosing one. You can just look at them below to figure out which model to purchase.

  • Fuel Type

One of the most important factors that you need to consider is the fuel type or the ignition type of the product. Most of the tankless based water heaters are available in two different sections. Some of them are electric-based fuel while some of them are Propane based. The propane-based models are easily available at a lower price.

  • Location and Size

Another important thing that you need to consider is the location and altitude of the installation. If you are installing it at a higher altitude, you need the product to be compatible with extreme temperatures. Similarly, you need to consider the size and the requirements you have. To know the size, you need to understand how many people are using the heater at the same time.

  • Application

Knowing where you will use the product is an important consideration. You need to know where you are willing to use the product and what the applications are. If it is for a bath, you will need a higher rate of flow. At the same time, if it is for small objects like dishwashing, you need to pick a product with a decent rate of flow.

Frequently Asked Questions [FAQs]

Q1. Can you install a tankless water heater outside?

A1. Of course, you can and this is the reason why outdoor units are manufactured. That’s the reason why the manufacturing procedures for an indoor unit and an outdoor unit are different from each other. They are built to withstand the elements. The outdoor units are prone to deal better under extreme temperature drops.

Q2. Do you need a permit to install a tankless water heater?

A2. Generally, no law can stop you from installing a tankless water heater. However, there are certain things that you must look into before installing like the amount of NOx emission and also the warranty. If you do it all by yourself, you may lose the warranty for some of the products. So you need to be specific before choosing.

Q3. Are tankless gas water heaters worth it?

A3. If you are comparing it with an electric heater, they are both different in operation. The latter will consume more electricity as you keep using the product. However, the gas-based heater will only consume a certain amount of Propane gas to perform. Both of them are efficient in their way. If you have a short budget, you can go for the electric tankless heater.

Q4. Can you run out of hot water with a tankless water heater?

A4. Most of the outdoor units are designed to provide you with instant hot water. The heating element is placed on the outflow pipe that allows you to receive the heated water. If you do have a continuous flow of water from the tap, you will also have a continuous flow of hot water inside. You will never run out of the hot water unless you turn off the heater.

Q5. What size tankless electric water heater do I need?

A5. The size completely depends on the requirements that you have. To be fair, the measurements of the tankless heaters are done based on gallons per minute. If the product has more GPM rate, it will be enough to serve the full family.


I hope that you have gone through the entire list of the outdoor tankless hot water heaters available. You can go through the entire review section to pick up the best match. If you just want the top choice product, you can also look for the Editor’s pick section. Do let us know about which product you liked the most and why it is the perfect one for you. Each of the products mentioned above come from a great brand service.