How Does a Tankless Water Heater Work?

Tankless water heaters are one of the best investments you can make for a modern home. The equipment works by using an electric element or gas burner to create hot water as it travels through pipes into the unit. This design ensures an almost endless supply of hot water occurs, delivering instant convenience and comfort.

When you see a tankless water heater work, the supply doesn’t have a storage place to manage. That’s why it is a cost-conscious conservation choice for homeowners today.

If you’re curious about how this technology works and how to choose one for your home, this short guide outlines the process from start to finish.

Tankless Water Heaters Work by Delivering a Hot Water Flow Rate

If you want to know how a tankless water heater works, you’ll need to know how many gallons per minute (GPM) of hot water your home uses.

Since a tankless system has a set capacity of how much water it can modify, you’ll need to measure how much usage you’ll have at once compared to what the unit delivers.

Here’s an overview of what you can expect from the fixtures and appliances that use water in your home.

Shower:	Between 1.0 to 2.0 GPM
Dishwasher:	Between 1.0 to 2.5 GPM
Kitchen Faucet:	Between 1.0 to 2.5 GPM
Bathroom Faucet:	Between 0.5 to 1.5 GPM
Washing Machine:	Up to 3.0 GPM

Those GPM ratings are based on current technologies for low-flow rates. For example, if you have an older faucet or shower head installed, the flow rate could 5.0 GPM or higher.

When you want to determine the GPM needed for your home, it is necessary to add the flow rating for all the major appliances, faucets, and fixtures you expect to run simultaneously.

A good rule to follow for a family of four is to add one faucet to the dishwasher and washing machine ratings. In the example above, a tankless water heater with a 6.5 GPM capacity should cover their needs.

What Is the Minimum Temperature Rise Rating?

Once you determine what GPM rating you need to have your tankless water heater work correctly, the next step is to consider the incoming water temperature. Although municipality water is somewhat regulated in this area, the ambient weather conditions play a role in how much heat must get applied to your water,

The average home uses water at 120°F or less to ensure the supply meets their needs. You can get away with a hot water flow between 100°F to 115°F in most other instances.

If you want to determine the minimum temperature rise rating for the tankless water heater, you’ll need to subtract the top reading you want with the outdoor water temperature.

Let’s say that you live in Minnesota. The entire state has an average groundwater temperature of 40°F or below. If you want hot water, you’d need a tankless system that could produce a temperature change of at least 60 degrees.

In comparison, if you lived in Florida with an outdoor water temperature of 70°F, you’d need a system with half of the capacity of the one required for a Minnesota home.

That’s why homes in the most northern climates typically receive a recommendation for tank-based hot water storage since the energy required to heat on-demand water would be potentially higher than a traditional installation.

What Else Do I Need to Think About with Tankless Systems?

When choosing a tankless water heater, you’ll need to think about an electric vs. gas system. The first uses an element to create results, while the second operates with a burner.

After you’ve decided what energy method to use for your tankless system, you’ll need to find a unit that matches your capacity and temperature rise requirements. A product like the Rinnai RU160iN is popular because it has a maximum 9 GPM flow rate with a BTU max that serves the average household well.

The final step is to look at the reasons why a tankless water heater would help your home. This technology offers continuous comfort, delivering an almost endless supply of hot water for showers, baths, or kitchen chores. Some systems protect your plumbing from scalding through advanced sensors and self-diagnostic programs.

A tankless system is convenient because it saves space and reduces the risk of flooding since there isn’t a tank that could fail. You can use this technology for up to 20 years (and often longer!), and ENERGY STAR® options are available.

How does a tankless water heater work? It delivers on-demand supplies so that everyone can have their needs met in your home.