Review: Airthereal Electric Tankless Water Heater “Evening Tide”

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Airthereal EVT-18K


Overall design






Ease of Use



  • Fast, energy-efficient heating.
  • Compact, wall-mounted design.
  • Very easy to plumb.
  • Multiple safety features.


  • Requires a dual 40-amp breaker.
  • Limited heating capacity in colder climates.

When we think about technology in our homes, we usually think about the eye-catching things. We talk about the latest game console, or our brand-new 70-inch LCD TV. Rivers of ink have been used printing articles about each successive generation of iPhone. All of this makes sense. After all, entertainment and media occupy a disproportionately large part of our brains. But there are other technologies that are even more important for your home. Take, for example, the various appliances you use in everyday life. The better they work, the better off you are.

Energy prices are going up, and hot water can be a significant part of your energy bill. Think of how much water you use on a daily basis. Now imagine heating all that water up on your stove. As you might imagine, that would put a significant ding in your gas or electrical bill. So if you’re trying to upgrade your home, a more efficient water heater is a good way to do it. And if you’re looking for cutting edge home appliances, Airthereal is a great place to start? They make all kinds of smaller appliances, such as their AGH380 air purifier. Since their small appliances work so well, we thought we’d take a look at their water heater.

We’re going to be reviewing the Airthereal Electric Tankless Water Heater. This is far from the only tankless water heater on the market, but it’s one of the easiest to use. It’s also reasonably easy to install, provided you’re handy with the electrical aspects. But those are just a couple of the things you should be looking for when you upgrade your water heater. To know whether the Airthereal heater is worth buying, you need to know a lot more information. You need to know what it’s capable of, both in terms of temperature and quantity of water. You need to know where it can be used, and how the interface works. Here, we’ll discuss those features, as well as everything else you need to know. Let’s begin!

Why Use a Tankless Water Heater?

Before we talk about the Airthereal “Evening Tide” EVT-18K water heater in particular, let’s answer a more general question. Why would you want to use a tankless water heater? There are several benefits, as well as a couple of drawbacks. Let’s take a closer look at why you should – or shouldn’t – use this kind of heater.

To begin with, a tankless water heater is significantly easier to install. Even a small traditional heater is big and bulky, and requires more than one person to get into place. A tankless heater, on the other hand, can be installed in any utility room, or even in a small closet. Because there’s no tank, it just doesn’t take up as much space. Along the same lines, tankless heaters are normally easier to plumb. Finally, a tankless heater is easy to get rid of at the end of its useful lifespan. If you’ve ever had to wrangle a full, broken 40-gallon water heater out of your basement, you’ll relate to this.

Airthereal Evening Tide Electric Tankless Water Heater

Another major benefit of a tankless heater is that you have unlimited hot water. Cold water flows in, and hot water comes out. If you want to stay in the shower for an hour, you can. With a traditional water heater, on the other hand, you have only so much hot water at a time. Eventually, you have to shut off your water and wait for the heater to do its magic. In the mean time, you can’t shower, wash dishes, or do your laundry.

Keep in mind that there is a downside of this. Even the most powerful tankless heaters can only handle so much flow at once. A traditional heater, on the other hand, can output much more water at once. You can shower and do laundry at the same time, as long as you’re not doing it for long. If you want more flow from a tankless heater, you may need to install a second heater.

The main reason a tankless water heater is more efficient is because it’s not keeping your water hot all day. Let’s say you have a traditional water heater, and you finish showering at 7:30 in the morning. You go to work, get home at 5:30, and wash your hands before preparing dinner. For that entire 10-hour period you were out of the house, your water heater has periodically been turning on. With a tankless heater, you’re only using power to heat the water, not to keep it hot. The only downside here is that you’re flash-heating the water, so you need a lot more wattage. The total power draw is still much lower, though.

The final main advantage of a tankless water heater is that it’s easier to maintain. With an ordinary water heater, you have to drain the tank twice a year. Otherwise, mineral sediment will build up inside, and end up ruining your heater. With a tankless heater, on the other hand, there’s no large tank of stagnant water. No scaling builds up, so you don’t have to flush anything out. Now that we know

Airthereal Evening Tide Electric Tankless Water Heater

Design & Installation

The Airthereal Electric Tankless Water Heater has a black aluminum-metal housing with a faux brushed finish. This makes it corrosion-proof and durable, as well as easy to keep clean. It’s rectangular in profile, and measures 17.25 inches high, 12.22 inches wide, and 3.43 inches thick. It’s also surprisingly heavy for the size, tipping the scales at 18.74 pounds. This is because inside the plastic housing, there’s a lot of metal piping and parts. The back of the housing is also removable, which is useful if you need to perform any diagnostics. That said, for ordinary use, you shouldn’t have to access the inside of the unit. You should only have to open it up when you’re wiring it.

Airthereal Evening Tide Electric Tankless Water Heater

At the bottom of the housing, there’s a pair of ¾-inch NPT connections, the standard size for interior main lines. Keep in mind that that’s not the same size as the pipe used for individual fixtures. Almost all interior fixtures use a ½-inch pipe. In other words, you’d use this heater somewhere along your home’s main line, not for a particular room. That said, if you want to feed some rooms but not others, you can. You’d just have to plumb another branch into the main line. This is obviously easier when your house is under construction, but it’s not always a big deal. If you have a big, unfinished basement, you can probably access much of the main line from there.

Airthereal Evening Tide Electric Tankless Water Heater

One thing to keep in mind is how many fixtures you’re trying to supply. In theory, the Airthereal water heater can supply hot water for two showers simultaneously. That’s about as much as you could reasonably expect from most full-sized water heaters. However, the temperature of the incoming water makes a big difference. The warmer it is, the more volume you can handle while still getting the water suitably hot. There’s a temperature chart on Airthereal’s website. It shows approximately how much volume you can expect to heat in your area.

Airthereal Evening Tide Electric Tankless Water Heater

Next to the water in and out connections, there’s also a power connection. Keep in mind that this is a powerful, 240-volt connection, so ordinary household wiring won’t do. You’ll need to use a pair of 8AWG braided-pair wires in order to safely wire in the heater. You’ll also need to install a dual 40-amp double-pole breaker in your breaker box. This is the most challenging part for most homeowners. Unless you’re very experienced with electrical repairs, you’ll want to hire an electrician.

Airthereal Evening Tide Electric Tankless Water Heater

The kit also includes all the gear you need to install the water heater. There are screws, anchors, and metal tabs for mounting it on your wall. Finally, you get a filter gasket that goes in the water intake. This keeps debris from getting sucked into your heater and damaging the internal components.

Airthereal Evening Tide Electric Tankless Water Heater

Performance & Everyday Use

So, what kind of performance can you reasonably expect? In the warmest parts of the country, you can put out 3.1 gallons per minute (GPM), enough for two bathrooms. However, in most parts of the country, one bathroom is a more reasonable expectation. In the coldest parts of the country, such as far northern Minnesota, the Airthereal “Evening Tide” EVT-18K will barely work at all. The water is simply too cold when it’s coming into the heating element. That said, you’ll get at least some coverage in most of the country. And if you want to use a tankless heater for your whole house, you can install more than one heater.

Airthereal Evening Tide Electric Tankless Water Heater

The temperature of the water can be adjusted as high as 130 degrees Fahrenheit. Keep in mind that this is very hot. Most people use 120-degree water if there’s any risk of children turning on the tap. To change the temperature, you simply press the “+” and “-“ buttons under the LCD display. There’s also a power button, so you can easily turn the heater off altogether.

Airthereal Evening Tide Electric Tankless Water Heater

There are several safety features built into the design, but there are two in particular you should be aware of. First off, there’s a thermal protection shutoff to keep you from getting burned. If the water temperature reaches 131 degrees, the Airthereal heater will automatically shut off. It’s also protected against running when the housing is dry. Unless there’s at least 0.475 GPM of flow, the heating element itself will remain cool. So if your faucet is at a trickle, the heater isn’t going to kick in.

Airthereal Evening Tide Electric Tankless Water Heater

Final Verdict

The Airthereal “Evening Tide” EVT-18K Electric Tankless Water Heater is a well-engineered piece of equipment. As major appliances go, it’s relatively simple to install. It’s powerful enough to supply the whole family, depending on where you live. And it’s designed with all the protections you need to keep yourself and your family safe. All in all, this is one of the most capable tankless water heaters on today’s market.

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