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What Homeowners Should Know About Tankless Water Heaters

A homeowner’s daily routine requires hot water. It’s necessary for showers and baths, washing the dishes, household cleaning, and doing laundry. They may take for granted that when they need hot water, it will automatically be available. 

But sometimes that hot water tank may break down or need to be replaced. Older hot water heaters are particularly inefficient. Those that need to install a new hot water heater may want to consider a tankless one.

In this article, homeowners will learn about the types of tankless water heaters, their pros and cons, and whether a tankless water heater would be a good fit for their home.

What Is a Tankless Water Heater?

grey tankless water heater

Water heaters are commonly known to have a large metal drum where the water is heated and stored for use. These appliances actually take up a lot of room and require frequent maintenance and repair.

Tankless water heaters, on the other hand, do not have a large tank where hot water is stored. Instead, the water is heated as it flows through a heat exchanger coil on an as-needed basis. These systems are also sometimes called on-demand, inline, continuous flow, or instantaneous water heaters. 

There are two main types of tankless water heaters: gas and electric.

Gas tankless water heaters use a burner to heat the water, fueled by natural gas. This type may be more powerful than the electric type, but because the pilot light is always burning, it is less energy efficient.

Electric tankless water heaters use a heating element that is powered by electricity to heat the water. This style is the most energy-efficient, but may not be able to keep up with household hot water demand.

Tankless Water Heater Pros and Cons

There are many advantages to installing a tankless water heater in their home, but there are also some disadvantages. 

drawing a cross

Some factors to keep in mind about tankless water heaters are:

  • PRO – Saves Money: Traditional water heaters with a tank lose a lot of energy by storing hot water, which eventually needs to be reheated. Tankless water heaters can be 24% to 34% more energy efficient.
  • PRO – Long Lasting: Tankless water heaters may last up to 20 years, whereas traditional tank water heaters only last 10 to 15 years, and require frequent maintenance.
  • PRO – On-Demand Hot Water: Instead of having to wait for the water to warm up for a bath, tankless water heaters provide instantaneous hot water. No more waiting around for a hot shower!
  • PRO – Versatility: Because tankless water heaters have such a small footprint, one can install multiple units throughout the home. Each appliance can have its own water heating unit, which is ideal for high-draw appliances such as washing machines and dishwashers. This versatility cancels out a few of the cons listed below.
  • CON – Initial Cost: The initial installation of a tankless water heater can be expensive, especially for the electric type, which often requires upgrades to household wiring and the electrical panel.
  • CON – Flow Control: Tankless water heaters have flow control, which enable them to heat a maximum of 2 to 5 gallons of water per minute, depending on the model. This makes it difficult to use multiple fixtures at once. Taking a shower and running the dishwasher at the same time, for example, might exceed the heating capabilities of the tankless water heater, causing the temperature of the water to drop.
  • CON – Temperature Rise: Temperature rise refers to how many degrees a tankless water heater must heat the water. In cold climates, the water supply may be naturally cold, and the water heater will have to work hard to bring it up to the desired temperature. For example, if the water supply is 50 degrees, and a user wants to bring it up to 100 degrees for a hot shower, that is a temperature rise of 50 degrees. A tankless water heater may not be able to handle the demand with such a significant jump.

When Is a Tankless Unit the Right Choice?


For homeowners thinking about installing a tankless water heater, they should first take into consideration how much hot water their household requires. Large family households consume a lot of hot water: up to 90 gallons per day. If the demand happens all at once, such as in the mornings when everyone wants to bathe, a tankless water heater may not be able to keep up.

They should also examine their budget. While tankless water heaters do offer money savings in the long run, the upfront installation costs can be a major investment.

Ultimately, an experienced plumber can help them decide if a tankless water heater would work for their home. And because the installation process can be tricky, they should also have their tankless water heater professionally installed.

Make an Appointment With The Plumbing Dr.

The Plumbing Dr. has been diagnosing and treating plumbing issues throughout Falls Church and Arlington, VA since 1979. Experienced and committed to customer service, The Plumbing Dr. can help with tankless water heater installation and more. They handle both residential and commercial plumbing and offer 24/7 emergency services.