9 Best Outdoor Tankless Water Heater Reviews (2019)


Best Outdoor Tankless Water Heater Reviews  

When it comes to the tankless water heater, there are many classifications in which you base your selection on.

It could be based on the type of fuel you prefer and/or the number of points the tankless water heater can serve at a time.

We also have classification based on the location of installation as some units are most suitable when installed either inside or outside.

Additionally some homes do not have proper venting for their water heater. Outdoor installation is the best idea for such homes because this removes the need for venting and ventilation pipes. It reduces the cost of installation considerably as there is little changes the house owner will have to make.

If you do not have a proper drainage system as well, an outdoor tankless water heater is highly recommended.

If you need or prefer an outdoor tankless water heater, you are in the right place. Many people want to get an outdoor heater but confused on the best model to buy. And honestly, with the abundance of outdoor tankless water heaters out there, it could be confusing to make a decision. This is why we put together the best outdoor tankless water heater review.

This review is the result of hours of research invested by our tech time. Of course, we cannot purchase all the tankless heater and use it. But we have read reviews from real users like yourself and made our judgment based on their feedbacks.

Whatever type of outdoor tankless water heater you prefer, we have outlined the best options per category, whether it be electric powered, propane gas powered or natural gas powered.

Moreover no matter what application and size household you need to cater for you will find credible options below.


Name Rating Prices Fuel Type Application type Location
Rinnai RL94eP 4.1 out of 5 stars (4.1 / 5)

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CHECK PRICE ON AMAZON Propane Whole House Outdoors
Camplux 5L 1.32 4 out of 5 stars (4 / 5)

Read Reviews


CHECK PRICE ON AMAZON Propane Single Point Outdoors
AQUAH Outdoor  4.5 out of 5 stars (4.5 / 5)

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CHECK PRICE ON AMAZON Propane Whole House Outdoor
Rheem RTG-84XLN  4.1 out of 5 stars (4.1 / 5)

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CHECK PRICE ON AMAZON Natural gas Whole house Outdoor
Takagi T-KJr2-OS-NG  4.2 out of 5 stars (4.2 / 5)

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CHECK PRICE ON AMAZON Natural Gas Natural Gas Single Point or Multipoint Outdoors
Rinnai V65EN 6.6 GPM  4.3 out of 5 stars (4.3 / 5)

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CHECK PRICE ON AMAZON Natural Gas Single point of use Outdoors
ECOTOUCH Electric Tankless  4.3 out of 5 stars (4.3 / 5)

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CHECK PRICE ON AMAZON Electric Single Point of use and Multiple Application Outdoor
Eemax EEM24027  4.7 out of 5 stars (4.7 / 5)

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CHECK PRICE ON AMAZON Electric Whole house Outdoors

Stiebel Eltron 24

 4.4 out of 5 stars (4.4 / 5)

Read Reviews


CHECK PRICE ON AMAZON Electric Single Point or Multiple Application Indoor and outdoor

Outdoor Tankless Water Heater Reviews

In this section we will go through each one of the models above and go through the specifications of each as well as pros and cons of the model.

We have grouped the models based on fuel types,

First off we will go through the best outdoor tankless water heaters based on propane.

Best Propane Outdoor Tankless Water Heater


Rinnai RL94eP Outdoor Propane Tankless Water Heater

  • Fuel Type: Liquid Propane
  • Application Type: Whole house
  • Location: Outdoor
  • Btu: 199,000
  • Gpm: 9.4 gpm
  • Energy Efficiency: 83%
  • Size: 14 x 10 x 23 inches
  • Weight: 44 pounds
  • Display: Digital
  • Warranty: 12 years on heat exchanger, five years on parts

First on our list of the best outdoor tankless gas heater is Rinnai RL94eP. This is an outdoor tankless water heater powered by propane. It is a very efficient unit which provides users with as much as 9.4 gallons of water per minute, with minimal demand for propane. It comes with an impressive propane saving capacity reducing your month to month expenses on propane, and It also enjoys pretty high-quality materials; hence, it can withstand harsh weather conditions.

The clean valves make it stand out from other tankless water heaters. It is also unique in that it can deliver hot water to heights as much as 185 feet. Hence, if you live in a story building, this will not be much of an issue. It is small, without the need for venting, compact and compatible with wall mounting.

It comes with a 24-hour programmable controller that offers extra convenience and helps with diagnostics. This gives you accurate monitoring of the temperature. The exchanger enjoys high-grade copper, which makes it appropriate for residential and commercial use.

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  • Economical use of propane
  • A pretty long warranty period
  • Can deliver water to heights above
  • It is an energy efficient unit

  • Installation needs to be done by an expert.

User Rating:

4.1 out of 5 stars (4.1 / 5)


Camplux 5L 1.32 GPM Outdoor Portable Propane Tankless Water Heater

  • Fuel Type: Propane
  • Application Type: Single point
  • Location: Outdoor
  • Btu: 340,000 BTU/hour
  • Gpm: 1.32
  • Energy Efficiency:
  • Voltage: 230 Volts
  • Size: 11.4 * 4.3 * 14.8 inches
  • Weight: 14.11 pounds
  • Display: Digital
  • Warranty: 1 year

For many that will like the idea of having portable tankless water for use on camping trips, beach house, vacation, etc., Camplux 5L 1.32 GPM is a good choice. This is an outdoor water tankless water heater that can be tweaked for indoor use with some modifications. It comes with a sensor powered by 2D batteries which makes it useful when electricity is not available. It is portable, saves energy and uses high-grade material

This outdoor tankless water heater enjoys advanced technology that saves water and gas. This makes Camplux 5L 1.32 GPM capable of giving impressive saving on your monthly water use. It is small and offers a remarkable temperature rise of 114.8F. The abundance of safety features also makes this unit worth considering. Some of the many safety features are antifreeze protection, which is not negotiable for outdoor water heater, oxygen depletion safety shut valve, overheat protection and flame failure device.

This is a functional unit for tasks like washing your cats, your dogs and other things around the house. It can also adapt without electricity, making it versatile.

  • Abundant safety features
  • Portable and compact
  • Impressive saving on water and fuel
  • Can be used without electricity

  • Cannot be used for drinking water

User Rating:

4 out of 5 stars (4 / 5)


AQUAH Outdoor Liquid Propane Gas Tankless Water Heater 10L / 2.7 GPM

  • Fuel Type: Propane
  • Application Type: Whole house
  • Location: Outdoor
  • Btu: 68,242 btu
  • Gpm: 2.7 gpm
  • Energy Efficiency: 85%
  • Size: 14 by 7 by 27 inches
  • Weight: 27 pounds
  • Display: Digital
  • Warranty: 5 years

If you stay in warm areas where the temperatures hardly go below freezing point, AQUAH Outdoor Liquid propane is a tankless water heater worth considering. It features automatic ignition and does not give standing pilot. It is a pretty versatile alternative as it comes with several accessories to make it easy to use by the owner.

This unit gives a temperature rise of 45 degrees with an efficiency of 85%. Being an outdoor unit, it was made with sturdy materials resistant to degradation and corrosion. The rain cap, for instance, was made of stainless steel to make it withstand adverse weather condition.

With a net weight of 29 pounds, it is lightweight and fit for external wall installation. While it is strong enough to handle the rain, you still need to protect it from the elements. It is strong enough to serve as much as 4 points at the same time

  • Can handle multiple points at once
  • Terrific customer support
  • Impressive safety features

  • Not easy to install
  • No antifreeze protection

User Rating: 

4.5 out of 5 stars (4.5 / 5)



Rheem RTG-84XLN 8.4 GPM Low Nox Outdoor Tankless Water Heater

  • Application Type: Whole House
  • Location: Outdoor
  • Btu:180,000
  • Gpm: 8.4
  • Energy Efficiency: 84%
  • Size: 14 x 10 x 26 inches
  • Voltage 120V
  • Weight: 54 pounds
  • Display: digital
  • Warranty: 12 years

Also on the list of our best tankless water heater for outdoor use is Rheem RTG-84XLN. This is an affordable unit for all and comes at the midrange size that can sustain a family of 4 with adequate hot water. We love the smart technology which helps controls the demand for energy. Thus, the rate at which it will use electricity and natural gas will reduce drastically.

A feature that stands Rheem RTG-84XLN out is the impressive water saving capacity. With this unit, you get as much as 1100 gallons of water in savings. This is because Rheem demonstrates efficiency both in operation and in the piping system.

This is a portable unit as well that can be wall mounted; it is sleek and compact. This unit can serve two or more bathroom efficiently with a flow rate of 8.4 gallons per minute without a reduction in your hot water temperature.

  • Sleek and compact design
  • Efficient in water and energy saving
  • Presence of a remote control

  • The unit needs special protection from the rain.

User Rating: 

4.1 out of 5 stars (4.1 / 5)


Takagi T-KJr2-OS-NG Outdoor Tankless Water Heater, Natural Gas

  • Application Type: Single Point or Multipoint
  • Location: Outdoor
  • Btu: 19,500 – 140,000 BTU/hr
  • Gpm:6 GPM
  • Energy Efficiency: 82%
  • Size:5″ H x 13.8″ W x 6.7″ D.
  • Weight: 38 pounds
  • Display: Digital
  • Warranty: 12-year heat exchanger, 5 year parts and 1 year labor.

Also on our list of best natural gas water heater for outdoor use is Takagi T-KJr2-OS-NG. This is a portable unit that can serve as a point of use or a multipoint application. It is a sturdy unit that uses classic and modern technology in heating water. This is your ticket to a constant supply of hot water.

Weighing 38 pounds, it is one of the top tankless water heater dedicated for outdoor installation. It is simple, compact and powerful enough to meet your needs. With an impressive flow rate of 6.6 gallons per minute, it is powerful enough to handle whatever you throw at it.

Hence, if you need to do the laundry and have a shower at the same time, Takagi T-KJr2-OS-NG will be of great help. It comes with a modulating burner which gives you control of the water and gas valve. There is a remote control that helps you control the water temperature. With an abundance of safety features, it is one of the best tankless water heater brands.

  • The device is durable and reliable
  • High flow rate, capable of serving many points at a time.
  • Impressive safety features
  • Presence of a remote control

  • You might need a dedicated gas line

User Rating: 

4.2 out of 5 stars (4.2 / 5)


Rinnai V65EN 6.6 GPM Outdoor Low NOx Tankless Natural Gas Water Heater

  • Fuel Type: Natural gas
  • Application Type: Single point of use
  • Location: Outdoor
  • Btu: 150,000
  • Gpm: 6.6
  • Energy Efficiency:
  • Size: 8 x 6.8 x 20.9 inches
  • Weight: 47.4 pounds
  • Display: digital
  • Warranty: 10-Year Warranty on Heat Exchanger, 5 Year Parts, 1 Year Labor

We also have this single tankless water heater meant for outdoor installation powered by natural gas. Rinnai V65EN works via an array of burners, heat exchangers and sensors. The sensor detects the flow of cold water and triggers the burner that raises the temperature of the flowing water via the heat exchanger. Being a point of use outdoor tankless water heater, we recommend it for small house, hotels, restaurants etc.

This unit is sleek and comes in a compact design which is meant to save space. With state of the art technology, the unit delivers at optimum capacity. Installation is easy but should be done by a certified expert to avoid voiding your warranty. We also love the abundance safety features that make this unit safe for use; we love the antifreeze feature, in particular, a necessity for an outdoor water heater.

If you need a tankless water heater for a constant supply of hot water, this is the ideal choice. You also get a digital temperature controller that allows you to set and lock a particular temperature for as long as you desired. This unit is an energy star certified which reduces demands on energy.

  • A pretty easy installation process
  • We love the safety features
  • It is compact and light in weight

  • Can only be sued by small homes

User Rating: 

4.3 out of 5 stars (4.3 / 5)

Best Electric Outdoor Tankless Water Heater 


ECOTOUCH Electric Tankless Water Heater Point of Use Hot Water Heater

  • Fuel Type: Electric
  • Application Type: Single Point of use and Multiple Application
  • Location: Outdoor
  • Btu: 70,000
  • Gpm: 1.2 – 1.5 GPM
  • Volt: 240 Volt
  • Ampere: 30Amp
  • Energy Efficiency: 98%
  • Size: 5 x 9.8 x 4.1 inches
  • Weight: 5.97 pounds
  • Display: Digital
  • Warranty: 5 years

Ecotouch electric tankless water heater is to be installed outside and can be used as single or multiple points of use application. Powered by electricity, it has an impressive overall efficiency of 98%, simplifying the process of delivering hot water to various points in the house without much power demands.  Being a single or multiple point of use heater, it is best for sink and other points in the house that needs hot water.

With the capacity to give a flow rate of 1.2 grams of water per minute, it offers a temperature rise of 42F. Water output from this devise is immaculate as the unit neither harbor bacteria growth nor is susceptible to rust.

This outdoor tankless water heater features a smart modulation technology, a trademark of ECOSMART, one of the top brands of tankless water heater around. This means that this device can limit power consumption based on the amount of water heated.

  • A simple installation process
  • Self-modulating technology makes it pretty efficient
  • We love the safety features like dry heat protection and leakage protection
  • Availability of remote control

  • Needs extra protection from the elements

User Rating: 

4.3 out of 5 stars (4.3 / 5)


Eemax EEm24027 Electric Tankless Water Heater Blue

  • Fuel Type: Electric
  • Application Type: Whole house
  • Location: Indoor/Outdoor
  • Gpm: 5.3
  • Volt: 240 Volts
  • Ampere: 112.5 Amp
  • Energy Efficiency: 99.8%
  • Size: 17 by 17 by 3.8 inches
  • Weight: 17.4 pound
  • Display: Digital
  • Warranty: 5 years leakage and 1 years part

Eemax EEM24027 is an outdoor tankless water heater powered by electricity. It is an excellent replacement for the old water heater and comes with many advantages that make it worthwhile. The demand for electricity is minimal and it does not compromise on hot water supply. It can be used for both commercial and residential heating purpose.

Eemax EEM24027 can comfortably handle two sinks and a showerhead at the same time for users in cold climates. For people residing in hot climates, they can use as many as four showers and sink at the same time. With a flow rate of 5.3 gallons per minute, it can comfortably handle the entire house. Its heat transfer capacity is superb, and it is guaranteed to last pretty long due to the stainless steel.

We love the self-modulating technology; one of the things that make Eemax EEM24027 stands out. This helps match demand on electricity to the quantity of water being heated. This unit is compact and can be mounted on the wall.

  • Great reduction in energy bills
  • Installation is easy
  • Compact size
  • Presence of self-modulating technology

  • Users need to buy an additional breaker.

User Rating: 

4.7 out of 5 stars (4.7 / 5)


Stiebel Eltron 24 Plus Tempra, Tankless Water Heater

  • Fuel Type: Electric: Whole
  • Application Type: Single Point or Multiple Application
  • Location: Indoor or Outdoor
  • Btu: 380,000
  • Gpm: 0.77
  • Volts: 240V
  • Ampere: 100 A
  • Energy Efficiency: 99%
  • Temperature: 86°F – 140°F
  • Size: 4.6 by 16.6 by 14.5 inches
  • Weight: 1 pound
  • Display: Digital
  • Warranty: 7 years leakage and 3 years part

Stiebel Eltron prides itself as a unit that can get you as much as 20% savings on your energy bills. This is a top rated tankless water heater that comes with many outstanding features meant for outdoor installation.

It stands out among the list of tankless water heater that we have here because various regulatory bodies certified it; among them is ANSI/UL SD. Hence, this device is entirely safe for use and does not experience standby heat loss. There is an advanced control system that controls the flow of hot water

Flow rate could get as high as 4.5 grams per minute, and the temperature raise ranges from 27F to 54F. This unit will reduce your energy bills. The overall cost of installation is reduced as there is no need for venting.

  • Unit is easy to install
  • Certified by regulatory bodies
  • Unit is not too pricey

  • The flow might be delayed at times

User Rating: 

4.4 out of 5 stars (4.4 / 5)

Advantages of Having an Outdoor Tankless Heater 

Going for an outdoor tankless water heater is worth it considering the following points:

  1. Direct and straightforward Installation, especially Gas

Installation of gas tankless water heaters is known to be pretty stressful. However, installing them outside removes the need to make any significant changes in the home, for instance, venting. Since the venting for outdoor tankless gas water heater is pretty short, condensation does not occur. This also removes the need for a drainage system which is ideal for people that do not have drainage.

  1. Cheap and Fast Installation

Choosing and installing an outdoor water heater is pretty straightforward. The reduced need for installation accessories and changes that would have been needed inside reduces cost and also makes installation straightforward.

  1. Outdoor Heaters Last Pretty Long

If you can maintain an outdoor tankless water heater and keep it away from the elements like wind and rain, they can last as long as the indoor type. Bear in mind that they are made from rustproof materials; hence, degradation from water is highly unlikely.

  1. Getting an Installation Point is easy

If you want to install an indoor tankless water heater, you might have to make some changes in your home. This is especially needed if you do not have the old heater type. An outdoor tankless water heater makes everything simple. Once your unit has access to the vital electricity or plumbing lines, installation is pretty simpler. This makes much sense if you are installing point of use electric outdoor tankless water hater

It is, however, good to install your outdoor tankless water heater very close to the points that need hot water. It could just be right outside your kitchen; for instance, this is to prevent the hot water from having to travel too much before getting to the point of use. The disadvantages of this are obvious, and you will likely wait a while and also spend much on piping installation

Disadvantages of an Outdoor Tankless Water Heater

While outdoor tankless water heater comes with many benefits, there are disadvantages as well. Hence, take note of the following before deciding to go for an outdoor tankless water heater.

The Need for Weatherproofing

This is the major setback of outdoor tankless water – the possibility of freezing. As a result, you need antifreeze protection for your heat exchanger. This is not negotiable if you are located in cold climate regions. Freeze protection device are powered by electricity and do require a different power supply. This leads to unnecessary energy cost. Fortunately, some outdoor tankless water heater comes with antifreeze protection as will be discussed below.

Outdoor tankless heaters are pretty Expensive

Compared to indoor tankless water heaters, outdoor units are more expensive. This might be because of the extra insulation or the fact that they work for all weather condition.

Risk of Vandalism

There is also the risk of theft or vandalism. This might not be a concern if you live in a safe and protected area where your device is out of reach of intruders. However, should there be a possibility of vandalism or theft, the cost of repair is usually on the high side. And in extreme cases, you might have to go for a new one.

Tips for Choosing the Best Outdoor Tankless Gas Heater

  1. Get Your Approximate Flow rate

For folks in large families with two or more bathrooms, you will likely need a whole house tankless water heater. Your choice will be an outdoor tankless heater that can serve the entire house constantly. If you have a small house as well, a point of use heater might be the appropriate choice. You need to get the flow rate right, so you do not undersize or overestimate your tankless heater which could come with consequences.

  1. Select a Sturdy Exhaust

If you are going for a gas tankless water heater, we recommend that you install it on the outside wall. The point of installation should be a location where the unit can breathe adequately. You also need a durable exhaust as it expels all wasted gas out completely, keeping you safe.

  1. Select the type With freeze protection

Since outdoor tankless water is usually mounted on the wall, they are prone to damage from the elements and bad weather. This might shorten the lifespan of the heater. People living in the cold region especially, places where the weather tends to be severe needs to take utmost care. With this in mind, we recommend an outdoor tankless water heater with freeze protection.


We hope that you have found our outdoor tankless water review guide informative in helping you choose the best models for your household as well as determine whether an outdoor tankless water heater is suitable for your household!

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