Tankless water heater, also called instantaneous water heater, is designed to heat water on demand.

When heating water this way, it might seem that providing an instant supply of hot water would require more energy than heating the water slowly and storing it in a tank.

However, because there is no need to reheat the water again and again as is the case with any tank-based water heater, tankless systems actually require less energy.

Since tankless water heaters are more energy-efficient compared to conventional storage tank water heaters, picking a tankless unit might be the appropriate move for your home. But before you make any decision and rush into buying a tankless water heater, let us weigh all their strengths and weaknesses first.


Electric vs. Gas-Fired

First of all, we must distinguish between gas-fired and electric tankless water heaters. In general, gas-fired units are more costly and more complicated to install. Their main advantage is that they can provide higher flow rates.

Gas-fired or electric also depends on what type of system you had before. A gas tankless water heater requires the installation of a gas line, unless all you’re doing is replacing and old unit. Having a gas line installed in your home can only be done by a professional and can get really expensive. It may still be cheaper than rewiring your home, though, which may be needed if your home’s current electrical circuit is too weak to supply a large electric tankless heater.

Weighing all pros and cons, we prefer electric tankless water heaters, which are also what we’re going to discuss in more detail in this post.

How Electric Tankless Water Heaters Work

Once you turn on a hot water tap, cold water starts its journey through the heater. The coils heat the water immediately. That’s why you don’t need to wait for the water to become hot for very long.

But electric tankless water heaters are limited by how much hot water they can provide at any given time, which is called their peak flow rate. Most systems supply hot water at a rate of 1-2.5gallons per minute. The largest whole house electric water heaters max out at about 5 gallons per minute.

Even though smaller units cannot provide a large household with enough hot water, you can easily solve this issue by installing two or more systems working in parallel.

Tip: Washing machines and dishwashers use a great deal of warm water, therefore, consider installing a tankless water heater to supply each of your domestic appliances separately.



Low Initial Costs

As a general rule, the price for instantaneous water heaters is higher than the price for tank-based systems, regardless of whether they use electricity or gas.

However, the former usually serves longer while causing lower operating and energy costs, which makes up for the higher purchasing expenses.

Also, the majority of tankless water heaters last for more than 20 years, much longer than tank water heaters. Moreover, crucial parts such as the heating elements can be replaced with relative ease, resulting in easier maintenance and repair.

Deliver Hot Water in a Flash

A tankless water heater provides a constant stream of hot water. This is a clear advantage over a traditional tank water heater that usually runs out of hot water sooner than later.


Another important point to consider is that a tankless unit takes up much less space when compared to a conventional one, due to the absence of the large water storage tank. By the way, this is another advantage that electric has over gas: Electric units are smaller.


A demand water heater can easily achieve 24%-34% in energy savings compared to conventional storage water heaters if you use 41 gallons of water a day or less.

In the case of households that use considerably more water on a daily basis, switching to a tankless water heater can save 8%-14% in energy consumption.

Significant energy savings of 27%-50% can be achieved if a tankless water heater is installed at each hot water outlet.


Electric tankless water heaters are considered a safe option for delivering hot water in any home. On the contrary, due to running on gasoline, a gas water heater may cause a gas leak. Even though you can mitigate risks by having required inspections done on a frequent basis and performing maintenance tasks, with electric heaters there are little to no issues regarding their safety.

The Best Electric Tankless Water Heaters

If you are searching for a solid electric tankless water heater to install in your home, the Rheem RTEX-24 is one of our favorite options. It’s a whole house unit that’s affordable, efficient, and highly popular. As for the best single-output system, we recommend Rinkmo. If you don’t like either one, you can find more electric tankless water heater options here.



When you go online you find people complaining about poor hot water flow or the water not being hot enough after they’ve installed a tankless electric unit. And it’s true, when you don’t size an electric tankless water heater properly, these are exactly the kinds of results you get.

In order to avoid such issues, you should size your new heater by determining the water flow rate and water temperature you use in your household. This allows you to make the best fit for your home without running into sizing problems later on.

In Conclusion

Tankless water heaters running on electricity are said to be one of the best options in their niche. They not only supply a seamless stream of hot water, but at the same time also lower your overall energy consumption; ready to lower your electricity bill?

Furthermore, it is guaranteed that electric on-demand water heaters operate smoothly and safely, making your life considerably easier and more convenient.