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So you’re looking for the best tankless hot water heater?
Then you’ve definitely come to the right place. As an alternative to those bulky, costly and wasteful water tanks, tankless devices are quickly taking the nation by storm.
As opposed to storing unnecessarily large hot water volumes, tankless heaters work by simply heating cold water in a matter of seconds as it passes through – see the difference?
Since you’re here, you’ve probably heard about all the wonderful benefits that these heaters bring into our homes and businesses. In addition to providing us with a continuous supply of hot water, these devices have been known to last longer than the tanked ones.
But that’s not all; a decent device will also save you a sizeable chunk of change on power and gas bills every month.
Sounds impressive, right?
I’m sure you see where we’re going with this. If you’re in the market for a great heater, we’ve done the hard yards and found the top 10 most popular tankless water warmers on the planet.
Don’t you just hate it when that electric bill comes at the last stretch of the month, and it’s like you’ve been paying for the entire neighborhood?
The Marey Power Gas 10L Digital Panel is designed to deliver an endless supply of hot or warm water with optimum energy efficiency. And what’s even more interesting is that you’ll never have to use your electricity to heat water again. Furthermore, the tankless heater from Marey is incredibly straightforward and easy to install and operate.
All in all, the Marey Power Gas 10L Digital Panel is the ideal appliance for anyone looking for an affordable and energy efficient heating solution. With its automatic ignition and simplistic design, the heater is already a shoe in for use in many households.
Similarly, our customers who are more environmentally conscious will be impressed with the heater’s gas and water saving capabilities. And while the batteries aren’t included, they won’t be running out soon since their only job is just starting the heater and not heating the water.
However, we have to point out the fact that the Marey Power Gas 10L Tankless H2O Heater might be a bit disadvantaged in larger households with an acute demand for hot water.
What we liked:
Smaller Gas Line Specs – The fact the Marey Power Gas 10L Digital only uses a 1/2” gas line as opposed to others that use 3/4” means that you won’t have to bust some walls open.
Energy Saving Design – This particular heater boasts of about 54 to 87 % energy efficiency thanks to adjustable water and gas control.
The Marey Warmer is by far the cheapest option in the market and even probably on this list too.
This device has one of the lowest installation costs compared to other models.
What could be better:
Low Output – At only 3.1 GPM, the Marey heater has a considerably limited water production. This means that simultaneous showers are definitely out of the question.
Issues in Cold Climates – If you reside in slightly colder regions, you may have to switch to low-flow fixtures.
Hands up if you’re fed up with those smaller heaters without tanks and their even lower flow rates. Don’t worry; we’ve all been there. If you’re trying to run a business that needs a steady supply of hot water or have a generously sized family (in which case you’re still in the family business), then you obviously need a heater built for the job.
Want to learn more?
The Rinnai Natural RL75iN not only comes with two different flow rates, but it also sports an impressive BTU of 180,000.
Can I be totally honest with you?
The Rinnai Natural RL75iN might just be one of the best and most convenient heaters on the market, but there’s one particular element that has users complaining.
It’s a well-known fact that Rinnai models are among the most expensive pieces of equipment, but as always, you tend to get what you paid for. So we can definitely expect very high-quality components and service from this bad boy.
Moreover, the fact that this indoor tankless heater can literally be installed anywhere makes it as convenient as it gets. But don’t take my word for it – get one for yourself and see what we’re talking about.
What we liked:
Boasts of 82 percent thermal efficiency thanks to the sealed combustion system for effective, energy saving water heating.
Comes with residential and commercial heating ranges of 98 degrees to 160 degrees F
The heater delivers 7.5 gallons of hot water a minute, making it possible for simultaneous showers.
The small size of 14 x 23 x 9.3 inches allows this Rinnai item to be flexible enough for wall-mounted installation which is very valuable and space-saving.
Can be converted to propane for those who do not like natural gas.
What could be better:
Some customers sighted that the Rinnai RL75iN might have a slight 30-second delay of water flow at the tap.
The entire system will require very careful and demanding installation procedures.
As the water temperature climbs, the indoor RL75i tends to decrease its GPM.
Don’t you just hate it when your electricity bill gets so high that it’s like you’re running an assembly plant in your living room?
Yeah, I’m sure we all know the feeling. Especially to those of us who still use massive water tanks and energy guzzling heaters. If you’re looking to live a greener and more eco-friendlier life, then it’s definitely time to get the Eccotemp FVI-12-LP.
The FVI-12-LP is a liquid propane fired, forced vent indoor heater that is engineered for average hot water production for those of us who need plenty more than just one hot water application.
But is this all the unit boasts of, or is there more to it than meets the eye?
Maybe the following features will help shed some light.
Small, versatile, high powered and super eco-friendly, the Eccotemp FVI-12-LP is the ideal match for cottages, vacation cabins as well as small to medium homes.
Depending on your lifestyle and intended application, you can also opt to use a 20-100 pound propane tank. But as with all other gas powered tankless models, you’ll still have to find a way to vent out the exhaust. Fortunately, Eccotemp was thoughtful enough to include a stainless steel kit for venting that we can quickly set up for wall or ceiling venting.
What we liked:
Incredibly energy efficient requiring only 2 Watts 1 amp during operation.
The Eccotemp High-Capacity FVI-12-LP Tankless Propane Heater is small and compact enough for use even in the smallest cabins.
After seeing some of the other price tags on our list, the Eccotemp FVI-12-LP is by far one of the most affordable units you will find out there.
Comes with an array of safety features for safe operation.
GPM is high enough for at least 2 bathrooms as well as demand for sinks, shows, dishwashers and other applications.
What could be better:
Due to its smaller size, homes with more than 2 bathrooms will find it hard to satisfy demand for hot water.
You guessed it; you’ll need to set up and make room for a venting system to exhaust the fumes.
We might not be quite sure what this says about the quality, but the Eccotemp FVI-12-LP does not come with a lifetime warranty.
On the contrary, the manufacturer really did a good job to make the IR245 worth more than its price.
The simple fact that this heater requires practically no maintenance makes it even more attractive in our books. We also couldn’t leave without pointing out that while the SioGreen IR245 POU Electric heater has been touted as mid-sized, it can only manage a maximum GPM of 1.2. So you can forget about simultaneous multiple applications.
What we liked:
SioGreen’s patented Quartz elements make it possible to heat water from 0 to 105 degrees in just a couple seconds.
IR245s PID governed units translate to zero lost energy and up to 60 percent power savings.
Unlike conventional, tanked heaters, the SioGreen Quartz Elements IR245 POU Infrared Elec Tankless H2o Heater does not incorporate any sort of corrosive components.
Since the unit eliminates the risk of Calcium or Lime deposit formation, the IR245 is perfect for areas with hard water or well water
Absolutely zero venting required, so she’s safe for indoor use.
What could be better:
The lower GPM of 1.2 makes it almost impossible to use two hot water applications at the same period of time.
Some customers have complained that their SioGreen IR245 POU units have minor leaks. These might just be individual defects or damages that occurred during shipping.
Running a quick survey here – so pop your hands up if you fit the bill.
Do you live in harsh winter climates where hot water is more than a bare necessity?
Or maybe you reside in a pretty large house where hot water is always being used for one task or the other.
Either way, we’ve found exactly what you’re looking for.
Offering high-powered performance, an incredibly high flow rate of about 9.5 GPM and an even higher price range, the Rheem 9.5 GPM Indoor RTGH-95DVLN Tankless Natural Heater is built just for you. The insanely high rate is more than enough for those of us with homes that house anywhere between 2 to 4 bathrooms.
A word of caution, however – the Rheem heater will need complicated venting systems to ensure there are no events of fume build up.
What we liked:
Since the RTGH-95DVLN 9.5 Heater incorporates their exclusive Low Nox system, we can literally install the heater anywhere we want.
Remarkably high flow rate (9.5) GPM that can serve up to 4 bathrooms simultaneously without dipping.
The unit is quite energy efficient with a 94 % energy rating even at 199,000 BTU.
For us convenience lovers, we can look forward to the Rheem-provided remote to control the unit from afar.
What could be better:
There’s really no other way to put it; Rheem has really set a very high price tag for the RTGH-95DVLN.
For a unit that can hit a max flow rate at 9.5 GPM, it really disappoints with a min rate of 0.26 GPM.
It’s those incredibly complex, high-tech H2O heaters that are as easy to operate as a fighter jet. But with today’s highly evolved, tech-packed heaters, it can be a tad difficult to find on that is super easy and straightforward to use.
There is some good news though; one brand has really made its mark to impress those of us who are technologically challenged. If you’re in the market for a water tankless heater that will just get the job done plain and simple, then check out the Rinnai V65EP 6.6 GPM Outdoor Low NOx Tankless Propane.
In addition to making your work much easier, the heater boasts of a generous 6.6 gallons of hot water per minute.
As promised, the Rinnai device gives a user-friendly interface with easy controls. This means that we do not have to suffer those fancy controls or those equally undecipherable instruction manuals.
It’s when a manufacturer is able to combine a spectacular piece of equipment with a price range that is not too hostile to our customers. Takagi definitely nailed this concept with their latest release in the form of the Takagi Outdoor T-KJr2-OS-NG.
This is just one of the reasons why users worldwide highly recommend this model for both smaller and midsized homes. Similarly, the T-KJr2-OS-NG is by far the smallest unit in the Takagi line-up.
We know what you’re thinking about.
Don’t be fooled by the mini size of the model. While the T-KJr2-OS-NG is the smallest unit from Takagi, it scores pretty high when it comes to technology.
In addition to being able to provide 6.6 gallons of hot water per minute, the unit also features an air-fuel ratio sense that checks the efficiency. This means that we get fewer emission levels and help conserve the environment.
The small unit also has temperature safety controls and will shut itself down in the case of overheating. Combine the compact size, incredible performance, and affordable price, and we have here the device worth taking home.
What we liked:
Superior construction that will last your family for over ten years.
Easy installation as indicated in the instructions.
Very affordable and cost-effective even while in operation.
Can be converted into a direct-vent unit.
A leader in safety features such as freeze protection, surge protection as well as troubleshooting.
What could be better:
Outdoor installation costs tend to run high, especially when you factor in the direct vent system.
The T-KJr2-OS-NG Heater cannot fulfill the needs of larger homes or commercial needs.
Loose connections may result in a serious gas leak, so call in the professionals.
Some customers have complained that their units become louder with time.
It’s because the FVI-12-NG has been reconditioned. Simply put, this means that your Eccotemp is either a return or it might have been a tad scratched or dented during shipping. Still, the units are designed to work as if they were brand new and even come with a warranty.
Are you ready for the best part?
Just by looking at the size and flow rate, you can tell that the FVI-12-NG High cap Tankless Gas Heater is built for small or medium water production. While the company may try to sell it as ideal for those of us who need one or two water applications, we’re not sure how practical this will be if someone starts taking a shower.
However, we’ll be the first to admit that the unit will feel right at home in smaller cottages, bungalows, apartments and vacation cabins. It’s all a matter of deciding whether the small scratches and minor dents will put you off or not.
What we liked:
Highly affordable unit that is also easy on the pocket after installation.
Extremely energy efficient and eco-friendly.
Small and flexible enough to install in even the tiniest of spaces.
Comes with a full warranty just like a brand new model.
Sleek, modern and attractive design that is easy on the eyes.
What could be better:
Not as sufficient for larger houses or commercial use.
Since the units are reconditioned, you should expect some minor surface scratches as well as dents.
Will require you to install the included venting system to the outside.
While the warranty is the same as a brand new unit, it is actually not a lifetime warranty.
Seriously, how do you cope with keeping a full tank of water constantly heated?
In addition to being highly inefficient and impractical, tanked heaters consume an unbelievably high amount of electricity. This is why you need a tankless heater for water that will not only save you time but also save your hard earned money.
Now that we’ve shown you all the ill effects of tanked heaters, let’s move on, shall we?
If you’re thinking of ditching your power guzzling heaters and settling for something cheaper, you probably want to go with a natural gas tankless heater. Not only are these more resilient and stronger, but they won’t be such a long stretch from what you’re used to. If we’re talking about natural gas, then the Rheem 6.4 GPM RTG-64XLN Low NOx deserves a solid mention.
Here at the review haven, we’re always looking out for our customer’s pockets and how we can help you save money. However, there are times when you do get what you pay for. So if you want something high quality and with a decent GPM, you’ll have to shell out some big bucks.
The Rheem 6.4 GPM RTG-64XLN Low NOx not only comes with a generous 6.4 GPM flowing rate, but it also incorporates a ton of eco-friendly features to boot. So if you do have a few hundred bucks to spare, then this model will pay for itself in the long run.
What we liked:
Helps us to conserve the environment with its Low NOx that cuts back on harmful emissions.
The higher flow rate can be able to serve multiple bathrooms or kitchens simultaneously.
Comes with extra frills such as a remote controller and thermostat wires.
What could be better:
While the flow rate is consistent at 6.4 GPM, areas with cooler climates may only get a fraction of that GPM.
Should only be installed outdoors under all circumstances.
Things to Сonsider
How We Tested
By this point, I’m sure you’re wondering who the quack we are and why we qualify to tell you a thing about these tankless heaters. Well, all you really need to know is that our team was reviewing tankless models when your folks were still talking about tanked heaters. Suffice it to say; we know our stuff.
However, we go to great lengths to ensure that all our products are tested and retested to make sure that they do what it says on the box. If anything is amiss, off place or just in the slightest funny looking, our team of reviewers will be all over it like white on rice.
In addition to carrying out our own tests under different climates, environments, altitudes and other factors, we also reach out to long-time consumers of these products. This way, we have an informed idea of what we can expect from our tankless devices in 10 years to come.
C’mon; you didn’t think we went to the future now, did you?
All Types of Tankless Hot Water Heaters
Check this out:
In the end, it’s all about getting the right tool for the right job. Before you shell out your hard earned money for a killer heater, it’s important to understand all the different types of tankless heaters out there.
When you hear the terms gas powered or electric, you should be able to see more than just a power source. Our extensive testing and retesting showed us that there are a whole lot of variables that need to be considered before you decide what type of heating system you’ll be installing.
Enough chit-chat, we’ll have time for all that in the shopping guide below.
But for now, I’m sure you want to see how each of the different types work right?
Yeah, I thought so. And we’re going to start with Mother Nature at her very best.
Natural Gas Heater
Getting your natural gas might be simple, but the tankless heaters for water are a bit more complicated than that. In a tankless, natural gas powered heater, cold water is drawn directly into the unit where it proceeds through a quick heating process. Basically, the water is passed through a series of burners and heat exchangers where it is warmed to your desired temperatures.
Since natural gas-powered units are able to handle incredibly high volumes of water, they are more than ideal for large homes. They’re also quite familiar with most of us who live in freezing climates all year round. Now, naturally (pun intended), natural gas will always be cheaper than electricity.
So when it comes to both long-term utility perspective and saving money, a gas powered model might just be the best tankless hot models on the market.
But wait; A word of caution for all our esteemed visitors.
As always, every type of tankless devices has its own limitations. For the gas powered units, the biggest drawback is always the upfront cost. This means that a gas powered model is more expensive than electric powered. Furthermore, the fact that these heaters emit fumes means that we’ll have to vent all the emissions outdoors.
Fortunately, most brands already anticipate this issue and take all the right steps to sort it out. If you’re buying a gas or propane powered tankless heater for water, then chances are that they will include a proper venting kit with the purchase.
This way, all we have to do is install the venting system to exhaust fumes either from walls or through the ceiling. That’s definitely a small price to pay for efficient heating capabilities.
Propane powered heaters work pretty much the same way as natural gas-powered models. The cold water is drawn directly into the unit where it then proceeds through a quick heating process. The water is then passed through another series of burners and heat exchangers where it is warmed to your preset temperatures.
However, there are some differences when it comes to how methane and propane burn. These differences are the ones that affect factors like energy efficiency, cost, as well as longevity of the unit. Propane units seem to provide more power and as a result, they offer us some of the highest flow rates on the market.
Some of these models can even hit an impressive 9.5 GPM. However, propane gas is also infamous for its higher levels of emissions. As such, users will need even more ventilation. This means plenty of maintenance and cleaning as compared to the other types of tankless items.
There’s no other way to put it; tankless electric heaters for water are by far the most affordable option. In addition to costing a lot less up front, they don’t require nearly as much maintenance as the other gas-powered models.
However, this does not mean that they skimp out on performance. When it comes to quality and performance, electric heaters can match their propane and natural gas counterparts pound for pound. However, they cannot possibly supply as much power as the other heavyweights.
But here’s the interesting thing.
Aside from the fact that they are cheap to purchase and require virtually no maintenance practices, the tankless electric power models are popular for other reasons. They are smaller and compact enough to install practically anywhere in your home. We’re talking under sinks, in closets, over shelves, or just next to the hot water applications.
However, their smaller size means that they are only suitable for smaller homes that have slightly lower intermittent water needs.
Heater for RV
When it comes to tankless heaters, even recreational vehicles have caught on. After all, you still need hot water in the kitchen and bathroom even while RVing across the countryside. However, you have to consider a couple of factors.
Since your RV has limited space, you obviously want something small and compact. Similarly, you also want to make sure that you get as much venting in there as you can. The fact that RVs are in constant motion helps make exhausting any fumes very easy. Since RVs are also limited when it comes to a power source, you will also have to go with a gas-powered model.
Rinnai Tankless Devices
Allow me to shift your attention to something here real quick; if you’re new to the world of tankless H2O heaters, you’re going to want to go with the simplest, most recommended model.
We’re talking about:
In a world where tankless heaters are getting really complicated, Rinnai comes to the rescue. Much to the relief of many technologically challenged people, one brand has really made its mark to impress us.
If you’re in the market for such an item that will just get the job done plain and simple, then check out the Rinnai tankless heaters for water that make work easier, faster and more efficient.
Riddle me this if you will; just exactly how much maintenance does a tankless heater for water need?
And what on earth does their maintenance include?
Don’t worry; we’ll share all this information to help you maintain your unit and get the most out of her.
Basically, tankless heater maintenance entails flushing the unit at least once a year. See, the biggest problem facing most tankless units is a buildup of lime and scale around the heat exchange elements. Not only does this compromise the lifespan your heater, but the lime also causes a severe impact on the efficiency of the entire system.
This often leads to longer burner cycles and a drastically reduced GPM. Flushing the unit helps clear any deposits and keep your heater free from mineral scale deposits and lime buildup.
Since tankless models do not have tanks that deteriorate due to years if storage, they tend to offer long-term reliability. However, each brand offers its own unique warranty policies. Make sure you check your manufacturer’s terms.
Typically, most manufacturers require the product to be serviced or replaced if it was bought from a genuine source.
But here’s what you really ought to know:
Warranties for these types of items are only applicable to the original owner of the product and valid only for the specified period. If in any case the heater was bought from an unauthorized dealer or you have tampered with the factory serial code, then you will not qualify for compensation. So make sure have proof of purchase and have the genuine article when claiming warranties.
How to Choose Tankless Hot Water Heaters
All right! We finally managed to convince you huh?
But before you make that purchase, you still have a couple of factors to hone in on and a few questions to answer.
Think about it; are you buying the heater for your home or a business. And just exactly how much use will you get out of it per day? And can you even afford the damn thing in the long run?
All these and more questions are answered when you consider the following factors when shopping for a tankless warm/hot device.
While some of the most popular electric models are as small as a book or shoe box, others like gas or propane powered models require more room for their valves, burners, and vents.
This means that gas powered units will definitely take up a lot more space than their electric counterparts. Make sure you picture where the heater will go as well as how much space you have available.
This is by far the most important factor to consider when buying a tankless heater for your home. You will have to calculate how many gallons of hot water you need the system to pump out every minute. Similarly, you will want to check up the unit’s BTU and determine if its suitable for you.
Generally, the bigger your house is, the more powerful your heater will have to be. Getting the power requirements right will ensure that your heating system is sufficient for your home or business’s hot water requirements.
Ah yes, the all-important aspect of the budget. In fact, most of us start considering the budget before anything else.
Basically, the more expensive models are usually gas or propane powered. However, that’s just the initial buying cost. They get cheaper as you use them. On the other hand, electric models are super cheap to purchase, but they tend to be more costly in the long run.
Step 1 – Turn off the main incoming water line to the house.
Step 2 – Disconnect supply line to old item if you were using a tanked system.
Step 3 – Disconnect power or heat source from the old heater.
Step 4 – After removing your tankless heater from the package, determine where you will place it. Make sure you allow for proper clearances to comply with state and local building codes.
Step 5 – Mount your heater on a wall, under the sink or anywhere appropriate.
Step 6 – Hook up the connectors; for gas powered units, hook up the ventilation. Electric models just plug in.
Step 7 – Turn on the water line and let it flow into the heater.
Step 8 – Hook up and turn on electrical lines for electric models and gas supply lines for gas models.
Step 9 – Light up the pilot light or switch and enjoy your hot water system with a much-needed shower.
Our Verdict and Recommendations
Congratulations for making it all the way to the end of the journey. We really appreciate taking the time to know your tankless water heaters a little bit better. Hopefully, our guide has made it much easier to narrow down the type of the item you’re looking for, or even managed to teach you something new. We’ve definitely done our part to inform and educate you; the rest is now up to you.
But just one more thing before you go!
We’re yet to announce our champion of the day and why we think this particular heater deserves a standing ovation. After much deliberation with our team of reviewers, we’re proud to announce the Rinnai RL75iN Natural Gas Tankless Water Heater as the best choice for H2O heaters; the undisputed champion on our list.
It’s a well-known fact that Rinnai devices are among the most expensive pieces of equipment, but as always, you tend to get what you paid for. So we can definitely expect very high-quality components and service from this bad boy. But don’t take my word for it – get one for yourself and see what the fuss is all about. Trust us, your family and customers will thank you munificently for it.