Best Outdoor Tankless Water Heater For High Altitude

Buyers Guide, Tankless Water Heater

best outdoor tankless water heater
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Table of Contents

Are you on the lookout for an unbiased review of the best outdoor tankless water heater?

Well, in this post, I’ll walk you through some of the best outdoor tankless water heaters available on the market.

Moreover, I would also be throwing light on various aspects of an outdoor tankless water heater in order to help you make an informed buying decision.

Lastly, I would be responding to the queries related to the outdoor tankless water heater review in order to help you clear your doubts.

But, before that, I would be needing a small help from you.

Are you willing to help me?

If your answer is “YES”, then all you need to do is to respond positively to a couple of questions that I would be putting in front of you in a while.

So, which is your favorite outdoor water heater brand?

How much are you willing to spend on your favorite exterior tankless water heater?

Which brand will you prefer out of the two, that is, Rheem outdoor tankless water heater, or Rinnai outdoor tankless water heater?

Alright, enough questions.

best outdoor tankless hot water heater

So, without any further ado, let’s begin…

Best Outdoor Tankless Water Heaters Review

Well, before we start reviewing some of the best outdoor tankless water heaters available on the market, please allow us to explain the shortlisting process that we follow to pick the “top-rated” products for review.

Does it make sense?

First and foremost, our team of experts does the brainstorming to come up with the set of parameters on which we would be evaluating the products.

In this case, the product is outdoor tankless heaters.

Once you’ve finalized the evaluation parameters, the next step is to assign weightage to each one of them which depends upon one’s ability to influence a buyer’s decision.

Moving further, during the evaluation, each product scores certain marks across the evaluation parameters.

And, finally, we sum up the marks and pick the “top 10” scorer for reviewing.

In case, you still have a doubt or query regarding the evaluation process, feel free to reach out to us, and trust me, we would be more than happy to assist you for sure.

Camplux 5L 1.32 GPM Outdoor Portable Propane Tankless Water Heater

The Camplux tops our list and definitely, there are numerous reasons for it.

Be it the pros, features, customer experience, convenience, usability, and of course performance, the Camplux outdoor tankless heater is bound to match your expectation if it will NOT EXCEED.

Not only is the unit small, compact, and sleek design but also comes with an anti-freezing protection feature.

The lowest water pressure starts at 2.5 PS and the output is 1.32 gallons per minute of hot water.

Just for your information, the device also features oxygen depletion shut-off protection.

Frankly speaking, most of my clients whom we recommended this idiosyncratic tankless heater are happy with its performance.

Quite a few of my clients have appreciated the usability, ease of operation, and hassle-free installation features of this unit.

Of course, the unit stands out from the crowd and is one of the best buys as per our understanding, in the “value for money” category.

Portability, energy-saving, and innovation are the three parameters that make this unit a unique and affordable offering for sure.

Definitely, the Camplux tankless water heater will save you a good amount of money in the long run.

So, after knowing about its amazing features, you might be inquisitive to know who should buy this unit, right?

Frankly speaking, the unit can be used for multiple purposes including camping trips, outdoor showers, bathing pets, mountain cabins, etc.

On the downside, the Camplux tankless propane water heater line isn’t recommended for very high altitudes, that is elevation above 2000 feet.

With a maximum power output of 28,000btu/hour and a flow rate of 1.32 GPM, the unit is bound to deliver high performance.

Moreover, the wall-mounted Camplux heater is powered by 2 “D” cell batteries, and the average battery life is 180 days.


Don’t hesitate from investing in this remarkable propane tankless water heater, and start reaping the benefits right away.

Trust me, the Camplux tankless has everything from safety features to performance.

In simple words, you can trust this little beast for all your outdoor hot water requirements without compromising on convenience, user experience, safety, and performance.

Do I still need to convince you?

Just, Go, and GET IT. (Read Customers’ Review on Amazon)

Rinnai V65EN Outdoor Tankless Hot Water Heater

Well, it goes without saying that Rinnai is a well-known and highly trusted brand that has managed to prove its mettle time and again.

The brand is known to manufacture high-quality, affordable, and innovative products.

And, the Rinnai V65EN without any doubt matches my expectation that I’ve with the brand Rinnai.

Frankly speaking, almost all the Rinnai tankless heater models are worth the investment if we ignore a handful of not very user-friendly models.

Trust me, I’ve been using Rinnai tankless heaters for quite some time now, and I can assure you it will never run out of water and create havoc or panic situations for you in cold climatic conditions.

Of course, you need to be accurate with the sizing in order to reap the maximum benefits from this little beast.

You don’t have to wait longer for the hot water because the unit is equipped with ThermaCirc360 technology that recirculates hot water through the pipe.

It can be easily installed in small and tiny spaces because of its small and compact design.

In fact, you can go ahead and install the Rinnai tankless in non-conventional places including the attic, closet, etc.

As compared to traditional water heaters, the Rinnai tankless claims to use up to 40 percent less energy, and one of the reasons for it is the negligible standby heat loss.

A traditional water heater has a life expectancy of 8 to 10 years whereas the Rinnai V65EN comes with an average life expectancy of 20 years which is almost twice the former.

On the downside, some of my clients have complained that the water pressure is less in certain settings.

Most of my clients have given positive feedback about the unit if we have left a handful of outliers.

They were satisfied with the hardware, gas lines, wire lines, and overall performance.

Even in our evaluation process, the Rinnai outdoor tankless water heater has outperformed its competitors on various parameters including efficiency, affordability, portability, etc.


I highly recommend this outdoor heater to all those who are looking for a high-quality product that comprises almost all the essential ingredients as well as provides exceptional customer service.

Not only is the unit energy-efficient, affordable saves space but also, backed by 100 years of user confidence and satisfaction.

Rather than overthinking, believe in the brand and invest if it suffices your hot water requirements.

GASLAND Outdoors BS158 1.58GPM 6L Portable Gas Water Heater

Well, you don’t have to worry at all even though you’re on a shoestring budget.

Trust me, there are quite a few good outdoor tankless heaters that made our list in the “affordable” category.

And, you guessed it right, Gasland BS158 is definitely one among them.

In spite of being affordable, the unit is equipped with all the “must-have” features for an outdoor tankless heater.

The outdoor heater is compact and lightweight so carrying it from one place to another wouldn’t be a problem for you at all.

To be honest, the manufacturer has given top priority to the safety measures which are clearly depicted from the safety features that the unit is equipped with.

For example, the overheating feature senses the abnormal surge in the heater temperature, and thus shuts it off.

In cold climatic conditions, the anti-freezing feature protects the unit from getting damaged.

Not only does the unit comes with a maximum power output of 41,000 BTU/Hr but also is capable of low water pressure start-up.

In fact, it just needs 2.5 PSI to start up and delivers a flow rate of up to 1.58 GPM.

Moreover, the unit is equipped with advanced combustion technology that helps not only decreased gas consumption but also reduces burning noise.

On the downside, some of my clients have faced small issues with the hose.


I highly recommend this outdoor tankless heater to all my clients who have got kids and pets in their house so that they could reap the maximum benefits of the safety and protection features.

Even though your kid has turned the tankless heater and forget still you’re safe as the safety features will shut off the unit automatically.

And, most importantly, all these idiosyncratic features, that is, from safety to convenience, you’re getting at an affordable price.

I don’t find any reason why one should opt for this if s/he has a budget constraint.

Takagi T-K4-OS-NG Tankless Water Heater

The Takagi T-K4-OS-NG is a powerful unit and comes with a maximum flow rate of 8.0 GPM which is sufficient to caters to the hot water requirement of small to mid-size homes effortlessly.

On top of it, the unit comes with a built-in venting system which makes the installation process hassle-free and less time-consuming, indeed.

The unit comes with an anti-freeze protection feature so you can use it in extreme climatic conditions as well without worrying about it getting damaged.

The T-K4-OS-NG weighs 34 lbs and is energy star certified.

Like the aforementioned outdoor tankless models, it also saves you a good amount of electricity bills and can be easily installed in tiny spaces because of its small and compact structure.

Furthermore, the unit is backed by 5 years warranty on heat exchanger, 3 years on parts, and 1 year on labor which clearly depicts the confidence and trust of the manufacturer in its offering.

However, you can only avail the benefits of a warranty if the unit is installed by a certified technician.

Definitely, the unit stands out from the crowd because of its performance and the longer duration of the warranty.

The unit is also equipped with a temperature controller which gives users better control over the device and makes the temperature change quick and easy.


I highly recommend this outdoor tankless heater to my clients who are looking for a powerful unit.

Needless to say, with a flow rate of 8 GPM and output power of 190,000 BTU, the unit is bound to deliver high-performance.

The unit is equipped with a copper heat exchanger so it is both rust and corrosion free, and as a result, it lasts longer.

On top of it, you also get lead-free isolation valves, pipe cover, remote temperature controller, and pressure relief valve in order to help you achieve an optimum result with ease.

Noritz NR66ODNG Outdoor Tankless Water Heater

The NR66OD is a great offering from the brand Noritz and is equipped with idiosyncratic features in order to help you achieve an optimum result.

Well, if you’re not aware of the brand Noritz, then let me tell you, it’s a pioneer in the water heating industry, and is serving the end customers satisfactorily for over 60 years.

And, the best part is, the outdoor tankless water heater comes with a water flow of up to 6.5 gallons per minute.

The unit is environmentally friendly and comes with low NOx emission.

Moreover, the 36 lbs NR662-ODNG is backed by 12 years warranty on heat exchanger, 5 years on parts, and 1 year on labor.

My clients have given good feedback about this unit in terms of ease of installation, efficiency, and performance.

The Noritz outdoor tankless water heater is compact, lightweight, and doesn’t require much space for installation.


I highly recommend Noritz NR66ODNG to all my clients who want are looking for a “value for money” outdoor tankless heater.

You can even save a good lumpsum on the installation process as it’s easy and you can expedite it on your own.

In simple words, the unit is highly efficient, economical, easy to install, and comes with multiple safety measures.

And, the best part is, all these superlative features come at an affordable price.

Rheem RTG-84XLN-1 Outdoor Tankless Natural Gas Water Heater

The RTG-84XLN-1 is one of the best offerings from the brand Rheem and is not only compact and secure but also reliable and efficient.

Moreover, the Rheem outdoor tankless water heater has a relatively long lifespan, and the credit goes to the components made of stainless steel.

Also, the unit comes with a replacement screw and O-ring kit.

The Rheem RTG is an environmentally friendly tankless heater and comes with ultra-low NOx emission.

Well, most of my clients were satisfied with the performance and also, the lifespan of the Rheem RTG.

On top of it, the unit is equipped with advanced technology and equipment that are designed to enhance both efficiencies as well as safety.

Not only that but also the unit has garnered attention because of its user-friendly display screen that keeps its user informed of temperature and maintenance settings.


If you’re not only looking for an endless supply of hot water but also a couple of important safety features along with durability, performance, and convenience, then definitely, the Rheem outdoor tankless water heater is for you.

To be honest, the self-diagnostic system, water-saving mode, maintenance mode, next-generation burner technology, and a long, never-ending list of countless other features make this outdoor tankless water heater an ideal choice for its users.

In simple words, if you’re using a tank-style water heater and want to upgrade it then definitely, the Rheem tankless could be a perfect fit.

Trust me, the advanced technology and the idiosyncratic features justify the price of this little beast.

Camplux 16L Outdoor 4.22 GPM Propane Tankless Water Heater

So, here I’m again with a Camplux model which my team thinks could be a great fit for small to mid-size homes because of its features and technology.

The unit is equipped with a digital temperature display in order to help you not only monitoring the temperature but also providing better control of the device.

Like the previous Camplux outdoor tankless heater models, this little beast is also equipped with plenty of safety features in order to protect you and your family against any unprecedented events.

The overheating protection prevents the heating of the device after a certain temperature by shutting off the fuel supply.

Similarly, anti-freezing protection protects the unit in extreme climatic conditions.

Well, with a maximum power output of 110,000 BTU/hour and thermal efficiency of 88.5%, the unit is bound to deliver high-performance effortlessly.

Needless to say, as compared to the traditional water heater, it consumes less space.

The 4.22 GPM Camplux portable tankless water heater is perfect for off-grid areas, camping, cabins, etc where electricity isn’t readily available as it can be ignited with 2 D cell batteries.

Not only does the unit features a simple design and high output structure but also, comes with a quality rubber/plastic water hose in order to help you with a better and hassle-free user experience.


The unit is very popular among my clients because of its affordability, efficiency, and most importantly, portability.

On top of it, these Camplux outdoor tankless water heaters are a perfect choice for outdoor showers, bathing horses, and other pets.

All in all, the device is a unique blend of superlative user-experience and idiosyncratic advanced technology resulting in higher efficiency and ease of use.

Noritz NCC300ODNG Commercial Condensing Outdoor Tankless Water Heater

So, here I’m with one of my favorite commercial outdoor tankless water heaters that are highly powerful and comprise a commercial-grade heat exchanger in order to help you achieve an optimum result.

Not only is Noritz NCC300ODNG capable of flow rate up to 13.2 GPM but also, can link up to 24 units with the help of an efficient system controller.

All I want to say is, the Noritz NCC300ODNG can easily handle your hot water requirement for any size of home.

In fact, you can run the shower, faucet, dishwasher, and washing machine simultaneously without worrying about the scarcity of hot water.

The little beast uses natural gas as fuel, and with 300,000 BTU/hour, the unit is bound to deliver high-performance.

Furthermore, the Noritz outdoor tankless hot water heater weighs 108 lbs and is backed by 5 years warranty on parts and heat exchanger, and 1 year on labor.


The Noritz tankless heater is equipped with advanced technology and superlative features that make it a great fit for commercial use.

You don’t need a huge space to install it, and the process of installation is neither tedious nor time-consuming.

Durability, robust construction, powerful performance, and energy efficiency makes this unit a top choice for the ones who have hot water requirement on a frequent basis and in huge amount.

Rinnai RU98EN 9.8 GPM Outdoor Ultra-NOx Condensing Tankless Natural Gas Water Heater

So, here I’m with yet another great offering from the brand Rinnai, and this time it’s a very powerful unit that is also environmentally friendly.

Moreover, with a maximum output power of 199,000 BTUs, and a 0.93 maximum energy factor, the unit is bound to deliver high performance.

The unit has a low NOx emission and meets the California and Texas Nox emission standards.

With a flow rate of 9.8 GPM, the little beast is capable of sufficing the hot water requirements of mid to large homes effortlessly.

Furthermore, the Rinnai outdoor tankless water heater is equipped with condensing technology that makes it highly energy efficient.

Just for your information, the unit claims to be up to 95% thermally efficient.

The installation process is newbie-friendly and doesn’t take much time.

However, I would recommend you hire a certified professional to expedite the installation if you’re a first-time buyer.

As per my experience, it will not take more than 30 to 60 seconds to supply hot water to the farthest fixture.

However, what I claim is in normal circumstances, in exceptional cases, the wait duration can increase a little bit.

Lastly, the unit is backed by a 12-year warranty on heat exchanger, 5-year on parts, and 1-year on labor for residential installation.


Well, if you’re looking for an outdoor tankless water heater for a large home to suffice the hot water requirements of 4 to 5 persons or even more, then definitely, the Rinnai RU98EN could be a great option.

It can easily provide hot water for a couple of faucets and showers simultaneously.

In case of installation, you need to be a bit careful as the unit requires a correct choice of gas pipe diameter vs. length of the run and proper venting.

Trust me, the Rinnai RU98EN is a great outdoor tankless heater, and worth the investment.

EcoSmart ECO 27 Electric Tankless Water Heater

The Ecosmart ECO 27 is an electric tankless water heater that is equipped with advanced technology and superlative features in order to help you with the best possible user experience.

Moreover, the ECO 27 is highly energy-efficient and claims to save you up to 50% on electricity bills.

The digital temperature control allows you to increment the temperature in the interval of 1-degree.

On top of it, the unit uses copper and stainless components to enhance the lifespan, durability, and efficiency as well as keeps the rusting and corrosion at bay.

Definitely, this little beast has a very compact and unique design, and as a result, you can install it in tiny spaces with ease.

Also, EcoSmart is equipped with advanced self-modulating technology to help you save on electricity costs as the unit uses the energy only when it is required.


The 27-kilowatt tankless electric water heater is ideal for use in apartments, townhomes, and other whole-home applications.

Moreover, the ECO 27 can easily handle the hot water requirements of a couple of showers simultaneously as it can provide a flow rate of up to 6.5 GPM in a warmer climate.

On the other hand, the GPM can fall drastically up to 3 or even less in extreme cold climatic conditions, and as a result, you would be able to use up to two fixtures simultaneously.

Lastly, and perhaps the most exciting thing about the ECO 27 is that it provides a lifetime warranty on electronics, exchangers, and elements which clearly depicts the trust and confidence that EcoSmart has in its offering.

Outdoor Tankless Water Heater Buyer’s Guide

This is an important section, and I request everyone out there NOT to skip it.

I would be walking you through all the important parameters that you shouldn’t overlook when it comes to buying an outdoor tankless hot water heater.


It goes without saying that pricing is an important parameter that can influence buyers’ decisions especially if you’re on a shoestring budget.

Needless to say, these tankless outdoor models are a bit more expensive as compared to their tank-style counterparts.

To be honest, if you’re ready to spend somewhere in the range of $500 and $1000, then you can easily get a good unit that will definitely suffice your hot water requirements.

Well, the price that I’ve quote doesn’t include the installation cost.

So, if you aren’t an expert at installation, then you’ll have to hire a certified technician for installing the outdoor tankless water heater.

In simple words, the total cost would be buying price plus the installation price.

Gallons Per Minute

Gallons per Minute is yet another important parameter that will tell you about the liquid flow that your unit can handle at a given temperature.

In case, you’ve heard this term for the very first time, then please allow me to explain it to you in a better way.

A shower uses between 2.0 and 2.5 GPM.

Similarly, a faucet uses somewhere between 2.2 and 2.5 GPM, in fact, it uses a bit less for a kitchen or bathroom sink and a bit more for a tub.

Furthermore, a dishwasher runs at about 1 GPM and a washing machine will barely hit 0.25 GPM.

Well, it’s really important to have a rough idea about these numbers so that you can figure out the GPM that you’re looking for.

Most GPM estimates are based on the fact that it is raising the temperature in the range of 30 and 45 degrees.

Let’s understand it with the help of an example.

5 GPM with a 45-degrees rise may be only 2.5 GPM with a 90-degrees rise.

What I’ll suggest to you is to be a bit more conservative in case, you’re buying an outdoor tankless water heater for extremely cold climatic conditions wherein the groundwater is colder.

British Thermal Units

BTUs/Hour is an important parameter and is generally mentioned in the product specification section.

If you couldn’t find it then ask the salesperson about it.

The BTUs/Hour will help you to determine whether a particular outdoor tankless heater is capable or not of handling the hot water needs in extreme climatic conditions.

I’m assuming that most of you would be aware of this parameter, in case, you’re new to it, stay with us, as we’ll explain to you everything that you need to know regarding it.

  • 1 BTU is enough to raise 1 lb of water 1 degree
  • A single gallon is 8.3 lbs, that is, 8.3 BTUs is equal to one gallon raised one degree
  • In the USA or even other parts of the world, groundwater temperature varies by location, the lowest being about 30-degrees in the USA
  • In order to get a comfortable shower, if I’m not wrong then most of us prefer at least 90-degrees. So, if you’re a resident of a colder zone where temperature can fall up to 30 degrees, then you need a unit that can raise the temperature by at least 60 degrees with a good water flow. Well, what I’ve discussed here is a bare minimum requirement, so prefer the temperature to be 100-degrees while others 115-degrees so do the calculation as per your requirement

Power Source

As we all know, mainly two types of outdoor tankless water heaters are present on the market, that is, gas tankless water heater, and electric tankless water heater.

Furthermore, a gas tankless water heater can be segregated into the natural gas tankless water heater and propane tankless water heater.

It goes without saying that both the models come with their own share of pros and cons.

But, if we talk about the efficiency, then definitely, the electric tankless units have an upper edge as they come with 99% heat transfer efficiency.

On the other hand, natural gas units are around 80% efficient.

However, we’ve also reviewed some condensing units that are as energy-efficient as their electric counterparts.

But, what we’ve discussed so far is considering the climate is warm.

In case, you’re planning to buy an outdoor tankless water heater for extreme climatic conditions, then I would recommend you to go for the gas outdoor heaters.

Many of you wouldn’t be aware of the fact that most of the electric units lose up to 2/3 of their efficiency in cold climates, while propane units remain as effective as in warm climates.

If we consider propane as fuel then it might seem to you a cheaper option in the short run.

On the contrary, the price of propane is rising faster as compared to electricity.


Definitely, sizing plays a crucial role, isn’t it?

Almost all the outdoor tankless models that we’ve discussed so far are small, compact, and sleek designed so that you can easily install them in tiny spaces.

In fact, some models can be installed in unconventional places as well such as the attic, closet, etc.

Needless to say, the tankless units take lesser space as compared to their tank-style counterparts.

However, I would urge you to keep two things in mind while buying an outdoor tankless hot water heater.

  • First and foremost, the building codes where you live. What I mean by it is apartments and mobile homes that comes with some legal limits such as how big or heavy things can you install, etc
  • Total space available for installation also decides the outdoor tankless heater size that you should opt for. Other than the size of the unit, you also need clearance on all the sides in order to avoid the consequences of overheating as well as catching fire


I’ve seen my clients ignoring this parameter when it comes to buying an outdoor tankless water heater and sorry to say, but later they REGRET doing so.

What I always recommend is looking for an outdoor tankless unit that comes with a good warranty period.

Anything above 5 years would do the trick for you.

The more the warranty period the better it is.

An outdoor tankless hot water heater with a longer duration simply shows the confidence and trust of the manufacturer in its offering.

For example, EcoSmart ECO 27 comes with a lifetime warranty on electronic components which is definitely something that will grab your eyeballs.

Energy Star Certified Models

I highly recommend my readers as well as clientele to give preference to the energy star-certified models.

Wait, I know many of you would be wondering what an energy star certified model means, right?

In simple words, a product earns the status of energy star certified ONLY IF it is cost-effective, energy-efficient, and environmentally friendly.

In order to acquire an energy star-certified model, the product must be tested to ensure that it meets efficiency specifications.

Interested to know more about the Energy Star Certification?

Check out the related FAQs.

Incoming Water: Hardness and Temperature

Well, the incoming water hardness and temperature are two important parameters that shouldn’t be ignored when it comes to buying an outdoor tankless water heater.

Let’s discuss each one of them.


If the supply water or incoming groundwater has a higher degree of hardness, then you must use a water softener.

Other than softening the water, you also need to maintain the outdoor tankless heater in a better way by flushing the unit and carrying out the maintenance process without fail.

Moreover, it is highly important that you soften the water before it starts getting heated because failing to do so will lead to the accumulation of limescale and calcium which will slowly and gradually destroy your unit.

Check out the map of the hardness of the water in the United States.


As discussed earlier also, if your incoming water temperature is 50 degrees Fahrenheit or below that then definitely, you’re better off with a gas-powered tankless hot water heater.

Electric tankless heaters might not be capable enough to raise the temperature to more than 30 degrees Fahrenheit.

As per my experience and knowledge, I can affirm that gas-powered outdoor tankless water heaters are best for extreme climatic conditions.

Why should I opt for an outdoor tankless water heater?

Frankly speaking, as compared to a traditional tank-based water heater, a tankless counterpart has more benefits.

In fact, if sizing is done properly, then a tankless outdoor unit can provide you with an endless supply of hot water as compared to a tank-style water heater.

Not only that but also, the tankless units are more energy-efficient as well as take less space for installation.

Most of the tankless outdoor heaters that we’ve reviewed so far last almost twice (20 years) as much as a tank-based water heater.

On top of it, the standby heat loss is minimal as the hot water isn’t stored in a tank in the case of a tankless water heater.

As per, tankless heaters can offer up to 37% energy savings. 

How does an outdoor tankless hot water heater work?

Well, in case, you’re a seasoned professional, then definitely, you would be aware of the working style of an outdoor tankless water heater.

What if you’re a first-time buyer and literally don’t have any clue about an outdoor tankless working mechanism?

Well, don’t worry at all, we’re here to help you with all the necessary pieces of information that will definitely help you in becoming a smart buyer.

Frankly speaking, all the outdoor tankless heaters work more or less in the same way.

They have a simple mechanism that heats the water on-demand and without the use of a storage tank.

So, as soon as you open a fixture such as a hot water tap, the incoming groundwater enters a heating chamber and is then heated by a powerful heat exchanger.

In simple words, the heat exchanger is the heart of a tankless outdoor water heater.

For those who aren’t familiar with what a heat exchanger is, it’s a tool that allows heat exchange between the sources.

In fact, other kitchens and household appliances do possess heat exchangers such as air conditioners, refrigerators, etc.

Some of the best outdoor tankless water heaters are made with different materials and are also, used for varying purposes.

So, always do proper research, and don’t forget to read a couple of outdoor tankless water heaters reviews before coming to a conclusion.

Outdoor Tankless Water Heater Types

There are mainly two types of outdoor tankless water heaters based on fuel types, that is, electric and gas outdoor tankless heaters.

The gas outdoor tankless water heaters can be further divided into propane and natural gas outdoor tankless water heaters.

It can be a challenge to identify the best outdoor tankless unit for your home if you’ve not done your homework correctly.

In order to buy the best-valued product, you need to be well aware of the advantages and disadvantages of both gas and electric models.

Gas Outdoor Tankless Water Heater

Gas outdoor models are either fueled by natural gas or propane.

  • Powerful and capable of heating multiple fixtures simultaneously
  • Gas costs less as compared to electricity as a fuel in most region
  • Can successfully heat incoming groundwater in cold climatic conditions
  • More expensive installation process
  • Emit emissions directly from the unit
  • Depending upon the model and placement, it might require ventilation

Electric Outdoor Tankless Water Heater

As the name suggests, electric outdoor tankless water heaters use electricity instead of gas to heat up the water.

Most of the electric models are small, compact, and sleek designed, and as a result, consume less space as compared to gas counterparts.

In fact, most of the electric outdoor tankless heaters are easy to install and doesn’t involve huge installation cost.

  • Environment-friendly as it doesn’t emit CO2
  • When it comes to affordability, portability, and installation, it has an upper edge over the gas model
  • No need for ventilation
  • Less powerful as compared to a gas unit, and so most homes would require multiple electric units to produce the same amount of hot water as a gas-powered unit
  • Electricity is fuel is more expensive than gas
  • Regular maintenance is needed due to limescale and calcium build-up

In layman’s terms, buying a single, large, gas-powered tankless hot water heater or buying multiple tankless electric heaters will produce more or less the same hot water as output for roughly the same initial cost.

Indoor vs Outdoor Tankless Water Heater: Pros and Cons

This is a frequently asked question, and today, I would like to end the age-old debate about the indoor vs outdoor tankless water heater in order to help you make an informed buying decision.

Does it make sense?

Pros and Cons of an Indoor Tankless Water Heater

1. Ideal for cold climatic conditions
2. Adds value to new construction
1. Gas tankless heaters need proper ventilation
2. Noisy operation
3. Condensation and leaks can cause issues

Pros and Cons of Outdoor Tankless Water Heater

  1. Ideal for the warmer climate
  2. Doesn’t consume space indoor
  3. Keeps the noisy operation, leaks, and harmful gases out of the home
  1. Risk of theft and vandalism
  2. A power outage can cause damage

How to Install a Condensing Tankless Outdoor Water Heater?

I’ve attached a self-explanatory video for your perusal.

In case, you want to download the outdoor tankless water heater installation instructions, then you can do it by CLICKING HERE.

Do I Need to Flush my Outdoor Tankless Water Heater?

It goes without saying that if you would’ve used a tank-based water heater, then you must be familiar with flushing a tankless water heater.

Nonetheless, if you’re not aware of how to expedite the flushing of a tankless water heater, then stay with us, we’ll help you understand almost everything related to the flushing of an outdoor tankless water heater.

Of course, an outdoor tankless unit needs flushing on a regular basis.

Flushing helps you to remove limescale buildup on the burners inside the outdoor tankless heater.

Most tankless water heaters will display an error code when flushing maintenance is required.

On average, an outdoor tankless heater requires flushing once in a couple of years.

It’s a known fact that minerals travel in the water supply, and the more the minerals in the water, the higher the level of water hardness.

In the case of an outdoor tankless heater, there is no tank available for sediments to settle in.

In fact, the sediment ends up collecting on the burner which may impact the performance adversely, if not removed on time.

If the sediments get accumulated on the faucet aerator, then it will lead to a decrease in water pressure due to the clogging of the aerator.

Furthermore, if the problem persists even after consistently cleaning the aerator, then it’s high time that you expedite the descaling of your outdoor tankless heater.

If an outdoor tankless heater is used by 4 to 5 people, then you’ll have to flush your hot water heater at least once a year.

On the other hand, if two people are using the outdoor tankless heater, then flushing would be required only after 18 months.

In case, you want to extend the flushing process for 3 to 5 years, then you’ll have to install a water softening system.

How to flush an outdoor tankless unit effortlessly?

I’ve attached a self-explanatory video for your perusal.

Steps for Flushing an Outdoor Tankless Unit

The level of expediting the flushing is easy, and it will not take more than 2 to 3 hours.

  • First and foremost, you need to remove the cover in order to access the connections under the outdoor tankless heater
  • Secondly, you need to verify that your outdoor tankless water heater has flushing valves installed if they aren’t, make sure that you get them installed
  • Turn off the gas supply
  • Once done, turn off the water supply
  • In the next step, you need to open the flushing valves and connect the hoses
  • Setup the bucket as well as a sump pump
  • Flush your outdoor tankless heater
  • Check the sediment filter
  • Open the water supply to the outdoor tankless heater
  • Lastly, turn the gas on to the heater

Outdoor Tankless Heater Maintenance Tips

Frankly speaking, if you’ve bought a premium or top-rated outdoor tankless unit, then you must maintain it properly so that it can last longer.

We already had an in-depth discussion on the importance of flushing and often should you perform it.

In the next step, you need to clean out the filter which can also accumulate if not many then some sediments, and as a result, can impact the heater performance adversely.

I’ve attached a self-explanatory video for your perusal.

Well, if you’re a beginner and have never performed maintenance before, then don’t be nervous about maintaining your outdoor tankless heater as I’m attaching a self-explanatory video that will help you out with the process without any hassle.

When you’re expediting the descaling process, it is very important that you try not to use store-bought descaling products as they might contain harmful chemicals that can run off in your tap water.

If possible try to use natural white vinegar as it is completely safe for humans to consume so even though you’ve consumed a little bit of it, you’re completely safe.

In case of doubt or query, feel free to reach out to us, we would be more than happy to assist you.


As promised to my readers, I would be responding to the queries related to the outdoor tankless water heater review so that you can make an informed buying decision.

Are outdoor tankless water heaters worth it?

Well, an outdoor tankless water heater comes with a lot of advantages as compared to a tank-style heater.

They use comparatively less energy because they heat water only when you need it, and so the chances of standby loss are almost negligible.

On top of it, they last almost twice (20 years) as compared to conventional heaters.

They are small, compact, and can be installed in small spaces.

In simple words, the outdoor tankless heaters are a unique blend of performance, efficiency, and longevity.

How long does an outdoor tankless water heater last?

If you’re using the outdoor tankless unit in the correct way, then it can last for almost two decades.

However, what I said is an ideal timeline and can shorten if proper and timely maintenance including descaling, flushing, etc aren’t done properly and regularly.

Wrapping Up the Outdoor Tankless Water Heater Review

Well, first and foremost, I would like to thank you all for being with us till the end.

Secondly, I would like to bring to your notice that I along with my core team member have put loads and loads of effort in coming up with this comprehensive buying guide on Outdoor Tankless Water Heater.

And, in case, you’ve liked our effort and want to appreciate us, then feel free to share this piece of information with the ones who are in need of it.

After all, sharing is caring isn’t it?

Cutting long-story-short, let’s get back straight to the topic without wasting any time.

I’ve repeated it time and again, almost all the Outdoor tankless water heaters that were made to our list are of high quality and worth the investment.

I can affirm that all these outdoor models have received positive feedback from our clientele.

Needless to say, these outdoor tankless models have performed extremely well in our evaluation test so only they are being reviewed by us.

The term “best” outdoor tankless heater is relative and not absolute so what may be best for you might not even cater to my needs and vice-versa.

So, always look for outdoor water heaters that not only cater to your needs but also fall well within your budget.

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