All You Need To Know About Electric Tankless Hot Water Heaters

Beginner Info, Tankless Water Heater

all you need to know about tankless electric hot water heaters
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Well, if you’re a first-time buyer or even a seasoned professional and looking for some really interesting piece of information, then definitely, you’ve landed on the correct post.

In this article, we would be answering some of the frequently asked questions related to electric tankless hot water heaters by our clientele.

And, we hope and believe that you might also be inquisitive about a few of them for sure.

In simple words, we’re here to help you make an informed buying decision.

What is the lifespan of an electric tankless water heater?

Frankly speaking, the life span of a high-quality electric tankless water heater can last up to 20 years if maintained properly.

Some of the models are brands that I’ve personally known and have referred to my clients are EcoSmart ECO Series, Stiebel Eltron, Rheem, Rinnai, Noritz, etc.

I’ve received enough good and positive feedbacks about these models from my clients in terms of efficiency, warranty, and lifespan.

Does an electric water heater have to be elevated?

In general, it DEPENDS.


I know you’re not here for this answer, right?

Frankly speaking, in order to know whether an electric water heater needs to be elevated or NOT depends upon several factors including model and type of heater, its location, etc.

If your water heater model comes with an ignition source then definitely, the ignition source needs to be elevated so that the source of ignition is NOT LESS than 18 inches above the floor.

At the same time, you also need to be aware of the fact that if you own an electric heater that has all its switching controls located above 18 inches from the water heater doesn’t need to be elevated.

The elevation is mainly needed for Propane fueled hot water heaters as it is heavier than air.

So, in the case of leakage, it will pool on the floor.

Definitely, elevating a propane water heater will reduce the risk but saying that it will completely eliminate the issue would be a wrong statement, indeed.

However, elevation could enhance the safety of any type of water heaters installed in a garage as it works perfectly fine with a parking bumper of some type.

Why do electric water heaters have pilot lights?

Trust me, electric water heaters don’t have pilot lights as in small flames for sure.

Rather, they comprise of lights popularly known as Bezels that can be red or green.

Well, the red one tells you when the water is hot, and the green one tells you if the unit is switched on.

However, if it’s a gas unit then it has the fuel to create a flame.

To be honest, many of my clients get confused with the fact that many gas hot water heaters, particularly the tankless models also require electricity to operate.

Frankly speaking, the fact that it is plugged in doesn’t mean it is an electric hot water heater.

How do you light an electric water heater?

In most of the electric tankless models, the recoil starters are located on the backside and no more than three pulls are required to get it started.

In fact, the starting of an electric water heater requires only two things.

Before anything else, you need to ensure that the electric unit is properly installed.

Once the installation process has been completed, you need to fill the unit with water.

So, the next question arises, how it’s done, right?

Well, this is done by opening the valve to let water in while opening a hot water valve on a fixture such as a sink or a shower in order for the air present in the tank to escape.

All of the air present in the tank needs to be purged in order to ensure the free flow of hot water to the faucet and shower when you turned on them.

The next thing that you need to do is to go to the electric panel and turn ON the breaker that is listed as “Water Heater”.

Moreover, you might find a disconnect switch located near the tank that you need to turn on.

The same philosophy and “rule” holds true for a “tankless” and “on-demand” heater as well.

You need to purge the air out of the hot water lines before turning on the power.

You don’t have to worry if you’re planning to replace your old tank with the new one as the installer would’ve already checked for the leaks.

In layman’s terms, once the heater is installed and turned on it will continue to operate automatically even after power outages.

How do I turn up an electric hot water heater?

Well, if you’ve owned an electric hot water heater in the past or currently have one, then you must be aware of its functionality, right?

For those who doesn’t have any idea, please allow me to explain it to you.

Most of the electric tank heaters come with access panels on the sides wherein you can adjust, repair, replace the heating elements or thermostat.

To make things easy for the end-users’ setting of a safe temperature is done at the factory itself.

However, my suggestion to you would be to test both the elements for continuity.

Even if one of the two elements isn’t working properly then the entire unit will struggle to deliver.

In fact, malfunctioning of one element will lead to elongated heating of water as well as increased wait time.

Many of the newbies does the mistake of increasing the temperature to recover from such a problem.

Frankly speaking, turning the temperature up can be a dangerous thing as well so try to refrain from doing so.

On the other hand, if both the heating elements are working fine, and STILL you want hotter water, then try to increase the hot water setting in small increments.

Definitely, you don’t want boiling water in your tank-based heating until and unless the outside temperature is freezing.

Similarly, if you own a residential electric hot water heater, then in most of the models, you’ll find two temperature dials under the two cover plates and most probably they would be facing you if you’re looking towards the electric heater.

However, if you’re planning to do any temperature adjustments as per your requirements, then definitely, I would suggest you should turn off the water heaters circuit breakers.

If you’re a resident of the United States, then you must be aware of the fact that they are usually 200 and also have a ganged breaker mostly 30 amps.

Nonetheless, if you want a slight increase in the temperature of the hot water then you don’t need to do the adjustments rather turn the upper dial up a little bit.

For further increase in hot water temperature, turn up both the dials a little bit.

At the same time, you need to be careful so that you can easily avoid scalding temperatures.

My suggestion to you would be to check the water temperature at a sink 24 hours after each adjustment.

Nevertheless, in the case of a gas water heater, most of the models comprised of a single dial.

You need to follow the same process along with the same precaution.

Why does my electric water heater keep shutting off? How can I fix it?

In most of the cases, it happens either of a faulty thermostat or heating coil.

Not only that but also a faulty circuit breaker or a fault in the circuit could cause the electrical supply to shut on and off.

Sometimes, if the breaker tripping happens, then the water heater unit will trigger the shutdown, every time hot water has been requested.

Some electric tankless heaters do come with timers that you can adjust to go on and off in order to save a tangible amount on electricity bills.

You can think timer as a rotating disk with adjustable stops and starts.

Well, it goes without saying that the electric hot water heaters are very generic in their heating components and thermostats.

As per my knowledge and experience, a rebuild kit will not cost you more than $50 and also, includes both upper and lower thermostats along with upper and lower heating elements.

The additional tool that you’ll require is a socket wrench that you can use to remove the heating elements.

I always suggest to my clients to turn off the breaker to the hot water heater and check the tightness of all the electrical connections at the top of the heater where the electric cable makes its initial connection and at both thermostats which are under panels or underside of the heater.

How does an electric water heater work?

There are mainly two types of electric water heater, that is, tank-styled WH, and tankless water heater.

Let’s discuss the working style of each of these so that you can make an informed buying decision.

Still, quite a few of my clients use tank-styled water heaters.

The tank-styled water heater uses electric resistance elements to heat the water.

Moreover, in a common residential hot water heater model, there are two thermostats, that is, an upper and a lower, and each one of them controls an element.

The upper thermostat is the master, and also contains a safety cutoff.

Well, when the upper thermostat sensed a decreased temperature, it sends power to the upper element where electricity flows through the element.

The element works on the principle of converting electricity into heat.

In most of the models that I’ve come across, I’ve found that the element is submerged in the water which is necessary to keep the element from burning out and popping like a fuse.

Moreover, once the upper thermostat senses that the water has reached the set temperature, what it does is, passes power to the lower element until the set temperature is reached.

Because the heat rises, the lower element does the majority of the work heating the water in the tank.

To be honest, the upper element can only heat the water that is at its level or higher.

And, is primarily used to provide quick heat when the tank capacity has been mostly used.

Definitely, variations exist, with more or fewer elements, at different power levels from 120V to 3-phase 480V, but I’m sure that the basic operating principles are the same.

On the other hand, a tankless water heater still uses electric resistance elements submerged in water, but it uses a much lower volume of water combined with more elements and more total power to heat the water as it flows through the unit.

The most powerful residential tankless water heaters can heat up to 8 gallons of water per minute and draw up to 150 amps, or 36, 000 watts.

How do you install a tank-styled electric water heater?

  • First and foremost, you need to shut-off the cold water feed to your existing water heater, and manually trip the breaker for the water heater
  • Once done, you need to connect a garden hose to the water heater drain. Open a hot faucet close to the water heater. As the water drains for a while, also open the TRPV aka temperature-pressure relief valve on the top or side of the water heater, using the toggle handle on the valve
  • Let the heater drain completely
  • Disconnect both feed hoses, that is, hot and cold. Also, disconnect the 240V electrical connection and the water heater
  • Now, you need to move the old heater off the stand
  • Before placing the new water heater, if your water is in the garage, then the stand should be in good condition and capable of supporting the weight of a full water heater
  • You need to understand that water weighs roughly 8 pounds per gallon. Moreover, if your water heater is in the interior living spaces, or in a closet, then you need to ensure that there is a drip pan “2” larger diameter than the water heater, to place the water heater into. Also, ensure that the drip pan drain port is connected to a PVC drain line that runs to the exterior
  • Moreover, if your old water heater didn’t have an expansion tank, get one. It is code in many areas, today
  • Place the water heater and rotate it so that the old hoses line up the best with the tank fittings
  • If your old feed hoses were the corrugated type, get rid of them. Buy braided steel jacketed feed hoses. They are more reliable and durable
  • Moreover, you’ll need to hook up and support the expansion tank. If your plumbing skills are lacking, hire a professional
  • Also, if you are on the west coast, the U.S., or in an earthquake zone, you will need approved earthquake strapping to secure the water heater to the structure in accordance with the IRC and manufacturer’s instructions
  • Connect your feed hoses. Make sure the heater drain valve is closed. When you connect the feed hoses, hand tighten them, then 1/4 to 1/2 turn with a wrench, no more, no less
  • Any hose with a gasket should be tightened in this manner, otherwise, you will damage the gasket and the fitting will leak
  • Also, connect the drain plumbing to the TRPV. It should discharge either to the exterior or within 12″ of the floor
  • Open the cold water supply valve to the water heater. Check all the fittings for leaks.
  • Remember the faucet you opened to the hot side?
  • Go there and wait until you get a steady stream of water without sputtering and spitting
  • Now connect the old electrical wires to the terminals on the new water heater
  • Go to your service panel and reset the water heater breaker
  • Lastly, ensure that your thermostats are set to the desired hot water temperature

Will an electric tankless water heater match the performance of a tank-type water heater?

According to the Partnership for Advancing Technology in Housing (PATH), and supported by Housing and Urban Development (HUD), further testing is needed to determine if electric tankless water heaters will match the performance of tank-type heaters.

In fact, traditional tank-style water heaters now have an efficiency of up to 0.94 energy factor ratings, making an electric tankless heater not as attractive of an option when it relates to energy efficiency.

Are you pleased with a switch to a tankless home water heater?

Please allow me to share the experience of one of my clients who recently switched from a tank-style electric hot water to a gas-fired tankless condensing boiler style water heater a couple of years ago.

In sum, I’m pleased with the reduced cost and increased energy efficiency, but there are some tradeoffs.

Things that I’ve liked

  • Trust me, they are much less expensive to operate – it doesn’t run at all when no hot water is needed
  • Hot water is at a constant temperature, and there is an unlimited supply- great for long showers

Things that I’ve disliked

  • They are definitely more expensive than a tank-styled unit.
  • Moreover, they are somewhat more complex to install than simple tank heaters too
  • They are also sensitive to water pressure and flow rate

Wrapping Up

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

Secondly, I would like to bring to your notice that I along with my team have put loads and loads of efforts in coming up with this comprehensive FAQs.

We’ve tried to the best of our capabilities to answer questions related to electric hot water heaters.

So, if you’ve liked our efforts 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?

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