Best Electric Tankless Water Heater 2021: Reviews + Buying Guide
We are willing to bet that many of you out there have never heard of an electric tankless water heater before, but they can actually be extremely useful tools. This is especially true if you happen to live in a smaller area.
As the name suggests, these products let you heat water without having to rely on a big, bulky tank-based water heater.
However, since they are a bit obscure when compared to tank water heaters, we figured that we would take a look at a variety of different tankless options and tell you what’s good and bad about each. If you want our opinion on the best electric tankless water heater, we say to get the Rheem 240V RTEX-24 Residential Tankless Water Heater.
A Spotlight On Some of The Best Electric Tankless Water Heaters in 2021:
Electric Tankless Water Heater Reviews
Stiebel Eltron Tankless Water Heater
We are going to open up our best electric tankless water heater list by taking a look at what is undoubtedly one of the most high-end tankless water heaters on the market right now.
The Stiebel Eltron Tankless Water Heater is definitely the option for you if you are the type of person who has to have the best of everything in their home and if you are the type of person who doesn’t have a strict budget to follow.
To illustrate the quality of the Stiebel Eltron Tankless Water Heater, let’s first take a look at the heating capacity of this water heater. At its peak, and during warmer weather, the Stiebel should be able to handle around 2 showers and a sink (or various combinations of that) with relative ease.
Now, we know that this is the first review on this list, so many of you don’t have a reference point to compare that to. But, trust us when we say that this is an extremely good thing to see and it is a sign that the heating capacity of this heater is amazing.
Furthermore, the Stiebel Eltron Tankless Water Heater has this really nifty “smart flow” feature. What does this mean exactly? Well, the heater is constantly measuring both the amount of water being used and its own heating capacity.
If it notices that more water than it can reasonably heat is being used, it will automatically decrease the flow to whatever systems it is hooked up to. While this may sound bad, decreasing the flow of hot water is a lot better than just straight-up cutting off the supply altogether. This prevents that unpleasant occurrence where you are in the middle of a hot shower and are suddenly blasted with cold water.
As you will see from a lot of entries on our best electric tankless water heater list, the Stiebel Eltron Tankless Water Heater is a very energy-efficient model. It wastes very little energy and it has a bunch of built-in smart features designed to ensure that the heater only ever uses as much energy as is necessary. This makes a real difference in your monthly energy bill.
EcoSmart ECO 11 Electric Tankless Water Heater
Following up on that last review, we are going to be taking a look at a tankless water heater that is basically the exact opposite of the one that we reviewed last.
Whereas the previous review was of a very pricey, high-capacity heated, the EcoSmart ECO 11 Electric Tankless Water Heater is designed to be a lower-capacity option that is also very affordable. Given that this is one of the better budget options on the market right now, it is definitely deserving of a spot on our best electric tankless water heater list.
Let’s start by talking about the most important things that you need to know if you are going to consider investing in the EcoSmart ECO 11 Electric Tankless Water Heater. You need to understand what the main purpose of this heater is.
This is not a heater that is intended to heat multiple fixtures at once. It only has a power output of around 13 KW, which is strong enough to consistently and quickly heat around one fixture (either a shower or a sink).
While this may be disappointing coming off of our last review, the EcoSmart is really meant to fill a different niche. It is better suited for very small applications. This is the option to use if you have a very small dwelling or if there is only one specific fixture that needs hot water (which can often be the case with small dwellings like cabins or cottages).
Of course, because this is a smaller heater, it is also a lot cheaper than many of the other entries on our best electric tankless water heater list. And when we say “cheaper,” we really do mean it. This is easily one of the more affordable electric tankless water heaters on the market today. A great option for those who want reliable water heating on a budget.
EcoSmart ECO 18 Electric Tankless Water Heater
For the next review on our best electric tankless water heating list, we are again looking at a water heater from EcoSmart. However, the EcoSmart ECO 18 Electric Tankless Water Heater is a bit different because it is a pricier, more powerful version of the last EcoSmart product that we reviewed (which was the Eco 11).
The Eco 18 has all the same energy-saving properties as the previous EcoSmart product that we reviewed. However, when it comes to heating capacity, the ECO 18 represents a noticeable improvement over its predecessor the ECO11. You can heat a lot more with this particular heater, although it will cost you.
Bosch Electric Mini-Tank Water Heater
Typically, one would associate Bosch with things like circular saws and power drills, but with the Bosch Electric Mini-Tank Water Heater, they have shown that they can produce very high-quality tankless water heaters as well.
We will say right up front, that this is not the option for those looking for something that is very high in heating capacity. The Bosch Electric Mini-Tank Water Heater is a relatively small heater and this is reflected in how much it can heat.
At the same time, the size of this water heater does bring some advantages. First off, it isn’t as costly as some of the bigger tankless options that you have seen reviewed on our best electric tankless water heater list. So, it is a decent budget option (although it isn’t the most inexpensive option on the list, it is close).
Secondly, the smaller size also makes this perfect for small areas. Bosch advertises this water heater as being good for RVs. While that is definitely true, you could also get a lot of use out of the Bosch Electric Mini-Tank Water Heater in a mobile home or cabin setting as well.
Rheem 240V RTEX-24 Residential Tankless Water Heater
For the final review on our best electric tankless water heater list, we are going to be taking a look at the Rheem 240V RTEX-24 Residential Tankless Water Heater. What is so special about this particular water heater that we decided to save it for last?
Well, this is one of the higher-capacity tankless heaters out there. This is true both for our review list and the wider market. So, it was a natural choice for this review list.
What do we mean when we say that the Rheem is high capacity? Well, it can comfortably support around 6 gallons per minute in ideal conditions. So, what does this let the heater support? Well, a sink uses around 2 gallons per minute. So, you could potentially wire up 3 sinks to this heater.
A shower also uses around 2 gallons per minute, so you could also do 3 showers. Of course, you can mix and match your heart’s desire. What’s somewhat more unique about the Rheem 240V RTEX-24 Residential Tankless Water Heater is the fact that it actually lets you support larger appliances that other tankless heaters struggle to support.
For example, the Rheem has enough heating capacity to support a dishwasher and an accompanying sink. You could even use it to power a washing machine. It is definitely a powerhouse.
Aside from its heating capacity, the Rheem is also a very durable water heater option. It comes equipped with multiple copper heating coils that you can trust to last you for a reasonably long time. Likewise, the Rheem 240V RTEX-24 Residential Tankless Water Heater also comes with a self-modulation feature.
For those who don’t know what this means, it is actually a feature that you have seen on other entries on our best electric tankless water heater option. Essentially what the self-modulation feature does is automatically regulate how much-heated water is being distributed.
This does two things. Firstly, it makes the heater more energy efficient. Secondly, it helps to prevent your hot water from shutting off suddenly.
Best Electric Tankless Water Heater Buying Guide
Something that we mentioned way back in the introduction to this article was the fact that tankless water heaters aren’t exactly common products. This makes sense since, after all, most people do live in either houses or apartments, both of which are generally equipped with reliable tank water heaters.
Because of this general unfamiliarity, people probably aren’t aware of things like what the benefits are of going tankless and what you should look for when buying a tankless heater option. This is something that we are going to remedy in this buying guide. We are going to talk about both the uses of tankless water heaters and how to pick out a good one.
How They Work
As you can probably guess (especially if you read our best electric tankless water heater list), tankless water heaters work quite differently from tank water heaters. Whereas tank water heaters keep heated water in a reservoir and distribute it as needed, tankless water heaters work by heating water on demand. So, there is a significant difference in how they work.
Benefits of Going Tankless
There are actually a lot of great benefits to going with a tankless model over the more traditional tank model. While tankless models aren’t common, they probably should be since they are very useful.
As you saw from our best electric tankless water heater list, one of the key reasons to go for a tankless water heater is because it is extremely energy efficient when compared to tank water heaters. A regular tank water heater will waste a ton of energy (on some inefficient models, up to 30% of the energy used can be wasted) both heating water and keeping it heated.
This is not the case with tankless heaters as they are extremely efficient. A high-end tankless option, such as the ones reviewed on our list, will not waste much energy at all. In fact, it is rare to find a tankless water heater that wastes more than 5% of its total energy use. Most are even lower than that, wasting only about 2 or 3% of their total energy use.
Energy efficiency is not only great for the environment, but it is also great for your wallet as well. If you are like most people, you will be absolutely shocked at just how much money you save on a monthly basis by switching to a more energy-efficient form of heating.
More Efficient Heating
If you live in a household with a lot of people, then a common problem that you may encounter is a lack of hot water. This is understandable since any hot water use depletes the tank and it can take a while for a large water heater to fill back up.
One of the best things about tankless water heaters is that they heat the water as needed and only for one specific application. A lot of people really only use hot waters for showers. If you are one of those types of people, a tankless option can be great since the tankless water heater will only heat up the water being used for the shower.
People using hot water in the sink or dishwasher won’t have any impact on the hot water going to your shower. Also, because the tankless water heater is only heating small amounts of water at once, the water gets heated up a lot quicker than when water is stored in a large tank.
Better For Small Spaces
It goes without saying that if you are in a small house, cabin, or mobile home, then you probably aren’t going to be investing in a big tank water heater. You simply aren’t going to have the space and it would be impractical for such a small living area.
This is where tankless water heaters (especially electric models, like the kind we reviewed on this list) shine. They are perfect for use in small living spaces like mobile homes and small cabins. They are great at this for two reasons.
First off, they take up no space at all. Secondly, they excel at heating small amounts of water quickly. Obviously, if you are in a small living situation, then you likely aren’t going to be using much in the way of water, so the tankless water heater becomes a really good option.
Picking Out A Tankless Water Heater
There isn’t a ton of work that goes into picking out the best electric tankless water heater. Generally speaking, the main thing that you want to focus on is capacity. Tankless water heaters will differ quite a lot when it comes to how much water they can heat at once.
Some tankless options can easily handle multiple sinks and showers at once, while some will really only be able to handle a single unit at once. Furthermore, you also have to consider the average temperature of wherever you live.
The reason for this is that as the temperature drops, the water gets colder and it takes more energy to heat it. So, naturally, the heating capacity of the tankless water heater will drop alongside the temperature.
Frequently Asked Questions (FAQ)
Are Electric Tankless Water Heaters Worth it?
If you’re passionate about energy efficiency or live in a small space, a tankless water heater is a worthwhile investment. Heating water on demand ensures that you won’t need a bulky tank in the home, and no hot water or energy will go to waste.
What are the Electrical Requirements for a Tankless Water Heater?
Most tankless water heaters will require a 40w amp, around 8 kW of power, and a voltage of 140. A miniature, tabletop-sized heater will obviously need less, but larger models may require more power.
Does a Tankless Water Heater Need a Dedicated Circuit?
As the amps on tankless water heaters are so small, they rarely need a dedicated circuit. Take all necessary precautions, but it’s usually perfectly safe to share with other appliances.
Is it OK to Turn Off a Tankless Water Heater?
Yes. In fact, it should be positively encouraged to save energy. Unlike traditional models, tankless water heaters supply hot water in an instant without the need to warm up first.
What is the Downside of a Tankless Water Heater?
The biggest issue with tankless water heaters is their limited function. These appliances can only supply hot water to one faucet at a time. You could not take a shower while somebody else does the dishes, for example. They’re also quite costly to install, though their energy efficiency tempers this somewhat.
Can a Tankless Water Heater Fill a Tub?
Yes. Tankless water heaters heat water as it runs. This means that you will not run out of hot water halfway through drawing a bath, no matter how oversized your tub may be.
What Size Tankless Water Heater Do I Need for a Family of 5?
You will need a tankless water heater of at least five gallons to satisfy this need. Being realistic though, a family of five would be better served with a traditional water heater – or, at the very least, a minimum of two tankless alternatives.
Can a Tankless Water Heater Heat a Whole House?
Yes, although how long the heat lasts depends on the size of the home. Smaller properties and apartments will stay cozy for longer when making use of a tankless water heater.
What Size Breaker Do I Need for a Tankless Water Heater?
This depends on the model of the water tanker that you use. Most can make use of a 40 amp breaker but some models, like the Stiebel Eltron, require 50.
How Many Amps Does an Electric Tankless Water Heater Draw?
The average tankless water heater will draw on 120 amps of power. A typical household electrical setup is only set to accommodate 200 amps of power at a time. This means an upgrade to your home wiring may be necessary.
Do Tankless Water Heaters Use a Lot of Electricity?
No, investing in a tankless water heater – even an electrical model – will save money on your energy bills in the long run. This cost-saving may go some way to assuaging concerns over the upfront expense of these appliances.
How Long Should it Take to Get Hot Water from a Tankless Water Heater?
Mere seconds. Unlike traditional water heaters, tankless models heat running water on demand. This is one of their biggest selling points.
Where Should a Tankless Water Heater be installed?
The safest location for a tankless water heater is a minimum of 24 inches from any combustible materials and the output hot water pipe of your property. If possible, install the water heater on the second floor of a home.
Should I Leave My Electric Water Heater on All the Time?
You could, but there is no point in doing so. Electric tankless water heaters supply hot water from the moment you request it. There is no need to warm up the tank by leaving it running when not in use.
Can a Tankless Water Heater Explode?
If the pressure switches in the heater are defective, then yes. Thankfully, all the models profiled on The Sized are confirmed to have passed safety checks and can be used with confidence.
Can You Run Out of Hot Water with a Tankless Water Heater?
No. Tankless water heaters heat water as it flows from a faucet. They do not store a finite amount of hot water. As long as water runs from a tap, it will be heated.
Is One Tankless Water Heater Enough for a House?
This depends on the size of your house, and how many people need hot water at any given time. A tankless water heater can only provide hot water to one faucet at a time. If you want multiple hot water sources to run simultaneously, you’ll need multiple water heaters.
What Maintenance is Required for a Tankless Water Heater?
About the same as any other appliance in the home. An annual inspection and routine maintenance check are highly advisable for your safety. In hard water areas, these checks should be upgraded to every six months.
Will a Tankless Water Heater Work if the Power Goes Out?
No. These appliances are not reliant upon the power to work, but they are typically managed through an electrical control panel. If this control panel has no power, it’s the equivalent of a cell phone with no battery. Tankless water heaters still need a power supply to maintain their function.
If, after everything that you have read on our best electric tankless water heater list, you still have some questions, we would encourage you to contact us.
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