Eemax Tankless Water Heater Reviews: Hot Showers For All

If you’re smart, endless hot showers for the whole family can be a reality with an Eemax tankless water heater.

Depending upon your situation, the largest model HA036240 is the best Eemax for you.

However, two of the smaller HA024240 model could be your best choice.

Plus, if you live near the Gulf of Mexico, the even less expensive HA018240 is a good choice. I’ll explain why, so keep reading.

Eemax Tankless Water Heater For Home and Business 240-Volt.

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Dependable Whole Home Eemax Tankless Water Heater

Eemax water heaters have been around for a number of years and they have a variety of sizes available for just about every possible hot water need at home. While some of the smaller units are effective as point-of-use tankless models, the overall design of the Eemax electric tankless water heater is best suited to serve as a whole home hot water system.

If you’re looking or a reliable tankless water heater, you’ll want to check out this brand and in particular – the largest in the lineup of 7 different versions we recommend. We found the Eemax model number HA036240 to be the best overall solution to provide plenty of hot water on demand throughout the average size home.

If you’re looking for a central water heating system that doesn’t take up too much space, this one is well worth a closer look.

Size Matters When It Comes to Hot Water

In this brief review, we will focus on this model primarily. But we will also list the six other models we also recommend, if you need less hot water. Since the HA036240 model is the biggest of these, it’s probably the best choice for most people.

The reason is that you should always opt for the largest capacity tankless water heater you can get. That’s the best way to ensure a continuous and never ending flow of hot water on demand – even when several different faucets or hot water appliances (for washing clothes or dishes) are being used at the same time.

And you never have to worry about wasting electricity, since these units are only activated when the tap gets turned on.

Incidentally, the number of each unit corresponds to the maximum kilowatts it uses. So in the case of the HA036240, it uses a maximum of 36 kW. At the other end of the scale is the HA008240 which has a maximum rating of 8 kW.

Here are all 7 models we recommend.

Compare All 7 Eemax Tankless Water Heaters

Models >>>HA036
Max KW3627241813118
Max Amperage Draw150112.510075544633
Required Wire Guage4 x 8 AWG3 x 8 AWG3 x 8 AWG2 x 8 AWG1 x 6 AWG1 x 6 AWG1 x 8 AWG
Breakers Required4 x 40 AMP3 x 40 AMP3 x 40 AMP2 x 40 AMP1 x 60 AMP1 x 50 AMP1 x 40 AMP
Height (inches)1717171711.511.511.5
Width (inches)21171714888
Depth (inches)3.753.753.753.753.753.753.75
Pipe Centers Distance9.81255.8755.8755.875

Easy Replacement Of Old Water Heaters

If you’re considering an Eemax electric hot water heater as a replacement for an existing tankless hot water heater, you’ll likely find any one of these models is a simple plug-and-play replacement for your current device. That means you can locate the Eemax tankless exactly where your existing hot water heater is.

It also means that connecting both the plumbing and electrical should be fairly straightforward procedures for the installer, costing you less money to have it set up for you.

Choose one of these Eemax tankless water heaters and what you’ll likely find is that any of these new models come with some significant upgrades from what you’ve used in the past.

Designed For The Home But Also Deployed Elsewhere

Each featured Eemax tankless water heater is designed and engineered to supply single-family homes with hot water on demand.

But several early buyers have demonstrated that these Eemax tankless systems can also be used elsewhere to provide needed hot water for workshops, office kitchenettes, and inside various church facilities, for washrooms and kitchens.

But the truth is – they simply are not suitable in all situations – primarily due to the electrical requirements.

That means that these Eemax electric tankless water heaters are not the best options for RVs, food trucks, or campers (in most cases) – simply because they require a 240 Volt connection and anywhere from 33 to 150 amps. The truth is that most RVs, campers and food trucks are likely limited to about 120 Volts.

How To Choose The Right Eemax Tankless Water Heater

There are two primary factors to consider when choosing the best model of Eemax electric tankless water heater for your particular situation.

Number one – consider how many people would be needing hot water at any given time.

Number two – determine how cold your incoming water is. Both factors are important considerations. If you overlook either one, you may opt for a model that is inadequate for your specific hot water needs.

Consider your home at it’s busiest times. That could be early morning weekdays when everybody wants the bathroom at the same time. Or it could be weekends when you have out of town visitors staying at your place.

Both scenarios mean higher demands for hot water, so plan accordingly so everyone is well accommodated.

Live in southern Florida? The Eemax electric tankless water heater HAO13240 can handle a shower and a sink at the same time. Click Here

Typical Hot Water Applications And What They Require

  • Standard Bathroom Sink – 0.5 gallons per minute
  • Kitchen Sink – 1 to 2 gallons per minute
  • Dishwasher – 1 to 2 gallons per minute
  • Standard Shower Faucet – 2.0 gallons per minute
  • Water Saving Showerhead – 1.5 gallons per minute
  • Washing Machine – 1 to 1.5 gallons per minute
  • Bathtub – 4 gallons per minute

So if you’re running two showers simultaneously, you should figure on needing 2 gallons per minute each (what showers typically use). Therefore you would need to allocate 4 gallons per minute for these two hot water faucets that would be running simultaneously.

If you live in the north, your groundwater is going to be colder by default. This means that the water needs a larger increase in temperature to make it hot enough for showers, washing hands, doing the dishes – and so on. So, you have to take that into consideration too.

Your best bet in terms of capacity is the HA036240 water heater by Eemax. But if your need for hot water is less than say a family of four or five might need, then one of the other versions might be a better fit and would save you some money.

Approximate Ground Water Temperatures U.S.A. EPA
Models >>>HA036
Ground Water Temperature
40 Degrees F3.
45 Degrees F4.
50 Degrees F4.
55 Degrees F4.
60 Degrees F5.
65 Degrees F6.
70 Degrees F7.
75 Degrees F8.
80 Degrees F9.

What Size Eemax Tankless Water Heater Do I Need?

Let’s say your ground water temperature (what is entering the house) is 65 Degrees F. (That would be the yellow colored zone in the map above).

And you want to run the shower, dishwasher, and kitchen sink at the same time. What size heater do you need?

Each of those water uses require 2 gallons of water per minute. For a total of 6 gallons per minute (GPM).

Now look at the chart for Ground Water Temperature of 65 degrees. Look to the right and you will see 6.1 (GPM) then look up to the top of the column to find the Eemax tankless water heater model you need. Click on that model number to see the current price.

Get The Best Click Here

A Significant Space-Saver

These Eemax tankless water heaters are compact units that mount onto a wall without the need for a huge storage tank. That’s the big advantage of any tankless water heating system – you’ll gain plenty of space since there’s no need to accommodate a big tank to house your ready-to-flow hot water.

Tankless systems kick into action when they sense a demand for hot water and they work efficiently to produce it. In about ten to fifteen seconds – you can enjoy a steady stream of hot water that never runs out.

Plus, the Eemax tankless water heater is relatively maintenance-free. This means that once you’re set up and have the thermostat set to the temperature you want – you’re good to go.

Old style tank type water heaters use more energy. That’s because they are constantly running to maintain the temperature of the water in the tank. And generally speaking, they require more work to maintain.

For example, you may have to drain that tank once a year to get rid of the sediment that tends to collect in the bottom. An Eemax tankless water heater spares you the hassle and saves you some cash in operating costs.

How Tankless Works

All tankless hot water systems operate on the same principle. The warmer the water is at the start, the less heating is required to get the water up to the proper temperature. So naturally, it takes less energy to bring the groundwater up to a comfortable shower temperature in Florida than it does in New York.

But it also depends on the demand for hot water in your dwelling. If you’re running multiple taps at once – the demand increases – therefore, you need a tankless hot water heater that can keep up.

No Exhaust Ventilation Required

Another great feature of electric tankless water heaters like the Eemax is that there’s no exhaust ventilation required, as there is with any gas powered hot water system. The systems are designed for indoor domestic water heating capabilities. But they are not designed to be used to heat water in a pool.

As a whole home hot-water tankless system, Eemax requires significant power. It’s always a good idea to check and double-check with your local electrician to make sure that your home’s electrical capacity can handle the Eemax tankless water heater.

These things only run when hot water is being used. But they do require significant power while running and you need the minimum electrical capacity in order to handle it. Some people overlooked this step and purchased anyway, only to realize later that their wiring couldn’t handle such an installation.

More About Eemax Tankless Water Heaters

Though not instant, the Eemax tankless electric water heater does provide hot water relatively fast. This water is consistent and never ending once it’s up to temperature. But it does take ten to fifteen seconds to get there.

The compact design means that you can accommodate an Eemax where you may not be able to fit in a traditional hot water tank.

It’s got a modern, stylish look and with its external digital temperature control that is readily accessible, you can adjust the temperature as you see fit in 1°F increments that range from 80° up to 140° F.

Eemax makes its heating elements from copper, while the fittings are made of brass to increase durability. Eemax is an energy-efficient hot water heater operating at 99.8% efficiency.

Live in Wisconsin or the southern half of Minnesota? The Eemax HAO18240 will provide 2 gallons of water per minute. That’s enough for a shower, or the dishwasher, or the kitchen sink. Click Here

For Peace of Mind – Leave the Installation To A Pro

It’s a relatively straightforward installation when you’re replacing an existing water heater and using the same electrical and plumbing connections.

But we always recommend having it installed by a competent professional. That’s the best way to enjoy worry-free hot water whenever you need it.

According to the manufacturer, it’s important to install the Eemax system in an upright position, in an area that is free of dust and humidity.

You’ll also want to locate it in an area where you have quick and easy access to your water heater.

Just be sure to allow 12 inches of clearance above and below the box itself, plus 6 inches on both sides as well as in front of the tankless water heating system.

Minimum Flow For Activation

Eemax electric tankless water heaters require 0.3 gallons per minute of water flow in order to activate the device. If you have less than that, the water simply will not heat up. This is how it manages power requirements. It’s based on the demanded flow rate of water plus the temperature of the water at the source.

An advanced flow rate design, and temperature sensors, are designed modulate the power to the heating elements to maintain the temperature at the user’s preference.

Indoor Installation Only

This water heating system is designed to be installed indoors only. But you could also install it in an outdoor location – inside an enclosure – as long as it is protected from sunlight, rain, splashed water, and any debris.

It’s also important to avoid freezing temperatures. So if you’re located in the north, you should also add insulation and some kind of heating system to the enclosure.

Here’s a Quick Fix For Preventing Cold Water

If you notice that your water is heating but it’s not at the desirable temperature, there could be a number of causes. The first thing to check is that you have adequate water flow. Less than 0.3 gallons per minute and you’re just not going to get hot water.

If the temperature is set too low, that could be the reason for cooler than desired water. If the flow rate is too high for your model of tankless water heater, it may be beyond the capacity of the device. That’s why it’s important to choose the largest model you can afford.

You can reduce the flow rate by installing an Eemax flow regulator, thus ensuring hot water where you need it.

Another possible cause of cooler than wanted water could be incorrect wiring. It’s not a DIY project, unless you have a competent professional electrician check the wiring to make sure everything is right.

How Far Does Hot Water Need To Travel?

Yet another factor to consider is the distance the water needs to flow from the tankless water heater to the faucet. The longer the route and the colder the pipes, the more likely it is that you’ll feel cold water initially. You may have to compensate for cooler water by increasing the temperature setting on the thermostat.


  • A tankless water heater helps reduce your carbon footprint because they use less energy (you only heat the water you need as you need it, so you’re not constantly heating a tank full of water)
  • You can have multiple showers running at the same time and the water remains as hot as you like (although the water pressure may be reduced slightly)
  • Costs less to operate than a traditional hot water tank system (you’ll save money every month)
  • Space-saving design (there’s simply no need for a large water tank)
  • Installation is relatively straightforward
  • Performs flawlessly and consistently
  • You’ll see savings in your electricity starting with your first month
  • It operates quietly
  • Manual temperature adjustment with a single dial which is easy to get to and use
  • It’s a stylish clean design
  • Durable build quality that should outlast a lot of competing brands
  • Offers good overall value
  • Heating elements are durable (made of copper) yet, like all elements, will need to be replaced eventually (and it’s easy to do)
  • Fittings are threaded and made of brass – should last longer than plastic ones competitors offer
  • With the Eemax tankless water heater – you will never run out of hot water
  • Installation manual is an easy read (though you do need to pay attention to the details)
  • Works well in a cottage or cabin for a shower and several sinks
  • Plenty of hot water means that nobody has to worry about a cold shower
  • Compact design and a clean installation
  • Even with cold ground water, the water coming out of the tap is hot and it only takes seconds (if you’re used to waiting two or three minutes for hot water – you’ll be pleased with this system as it takes less than 15 seconds to get hot water flowing at any tap)
  • It works well with adequate flow (without having to restrict the flow)
  • Stellar solution for smaller spaces


  • It’s not cheap (the upfront cost can be significant when you need additional electrical and plumbing supplies)
  • Takes a little while longer for hot water than a standard tank type hot water heater
  • Made in China (most consumer products are these days)
  • One user reported experiencing leaks from solder joints
  • You can hear this hot water system in operation from the room next door
  • It draws a large amount of electricity while operating (lights throughout the house can flicker while the water heater operates due to the electrical surge)
  • If you try to run more water through the system then it can handle, the water will barely be warm (that’s why you need to make sure that the model you select can handle your projected use)

Our Verdict On The Eemax Tankless Water Heater

The Eemax tankless water heater is a quality product – no matter what model you choose. We heartily recommend the HA036240 for any small or mid-size home.

That’s the best way to ensure a steady flow of hot water whenever you need it.

Choose your model based on estimated use at the busiest times and you can’t go wrong. Just be sure your home has the electrical capacity to handle it.

Eemax Electric Tankless Water Heater For Home and Business 240-Volt.

Check The Prices Of All 7 Click Here Now

An Eemax mini tank water heater can be an excellent addition to a whole house Eemax tankless water heater. Especially if you have a distant bathroom that the hot water must travel to.

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