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Kilowatt Heating, Air Conditioning and Electrical Blog

How Does a Tankless Water Heater Work?


It works great! We recommend looking into getting one for your next water heater installation.

Okay, obvious comment aside, people who haven’t owned a tankless water heater before are often curious about just how these systems work. They’re used to the standard type of water heater that most homes have used for a century: a large tank of water that’s kept hot (either with gas burners or electric heating elements) and ready for use whenever there’s demand for hot water. Remove the tank from the equation, and how does a water heater work?

We’re here to explain the basic operation of a tankless water heater. This information can help with your future water heater purchase decisions.

Tankless Water Heater 101

Tankless water heaters are sometimes called “on-demand” water heaters, and that’s a good basic explanation of how they work. A storage tank water heater keeps a supply of heated water ready, and it turns on at regular intervals to keep the water at the right temperature because the water inside gradually loses heat (this is known as standby heat loss). A tankless water heater doesn’t have a supply of water at the ready; instead, it heats up water “on-demand,” as it’s needed.

The mechanics of the process go like this: somewhere in a house, a tap or appliance comes on that’s requesting hot water. This causes the water in the hot water lines to start moving toward the tap, which also moves it through the tankless water heater. This motion triggers the water heater to come on. The gas burners activate (or electric heating elements turn on in an electric model) and transfer their heat to the water in the pipe that passes through the water heater. The burners continue to run for as long as the water is moving, i.e. as long as the tap or appliance continues to demand hot water. When the demand stops, the burners shut off and the water heater stops consuming energy.

The reason many homeowners find this process beneficial is that it 1) consumes less energy because there is no standby heat loss, and 2) means there isn’t a supply of water to deplete, so they won’t run out of hot water. The hot water isn’t “unlimited,” since it’s possible to overwhelm the heating capacity of the water heater if too many taps come on. But for many homes, a tankless water heater will mean a hot shower that won’t go cold.

Is a Tankless Water Heater Right for Your House?

Tankless water heaters offer many benefits: lower energy use, longer service lives, and a smaller need for water heater repair in Van Nuys, CA. But they aren’t ideal for all homes. For example, larger households may overwhelm a tankless water heater and cause it to lose efficiency. This is why we advise customers to always seek the assistance of water heater professionals when making a choice for a water heater replacement. You can put your full trust in our team to find the right type of water heater that will meet all your household needs.

Call our certified service technicians 24/7 for exceptional customer service! Kilowatt Heating, Air Conditioning and Electrical serves Los Angeles and the San Fernando Valley.

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