If you own a tankless water heater, you’ll need to take precautions to prevent it from freezing when the temperature drops below 32 degrees Fahrenheit. Also known as inline water heaters, tankless water heaters are designed to heat water on demand. Turning on a hot water faucet, for instance, will activate them.

They may not have a tank, but tankless water heaters can still freeze during the winter. Freezing, of course, can cause serious damage. As the ice within a tankless water heater begins to melt, it will expand. This expansion can rupture the tankless water heater or the water lines to which it’s connected.

Insulate It

Insulating your tankless water heater will better protect it from freezing. If there’s little or no insulation around it, your tankless water heater will be exposed to cooler temperatures. Whether your tankless water heater is installed in the basement, crawl space, garage or elsewhere, you should check to ensure it’s properly insulated. If you discover any open and exposed areas, fill them with insulation.

Let the Hot Water Drip at Night

You can protect your tankless water heater from freezing by allowing the hot water to drip at night. You don’t have to completely open a faucet. Rather, a small trickle of about 0.2 gallons per minute (GPM) should suffice. Just remember to let the hot water drip and not the cold water. Allowing the hot water to drip – even at just 0.2 GPM – will keep water moving through your tankless water heater.

Wrap Lines With Heat Tape

Another way to protect your tankless water heater from freezing is to wrap the water lines with heat tape. Heat tape is a type of conductive wire that’s designed to warm water lines. You can use it on the water lines coming into and going out of your tankless water heater.

Choose the Right Tankless Water Heater

Some tankless water heaters are better protected against freezing than others. If you’re worried about freezing, choose a tankless water heater with a freeze protection feature.

A freeze protection feature is a system that, as the name suggests, is designed to prevent tankless waters from freezing. They typically leverage an electric heating element. As the temperature begins to drop, the freeze protection feature will activate. The tankless water heater will then use an electric heating element to warm itself.

Keep in mind that tankless water heaters can only activate their freeze protection feature if they have power. Without power, they will remain susceptible to freezing. If the power in your home goes out, for instance, your tankless water heater may freeze.