Baby, It’s Cold Outside – Can Your Outdoor Tankless Water Heater Handle It?

Freezing temperatures can do a number on your home and no other part of it is more vulnerable than its plumbing. This is especially true if your home is equipped with an outdoor-mounted tankless water heater. These types of water heaters are popular in areas of the United States where temperate climates are the norm. However, unpredictable cold snaps could easily affect how your tankless water heater functions.

Most Units Offer Short-Term Freeze Protection

To ride out the occasional cold snap, most tankless water heaters utilize built-in freeze protection systems. These systems usually come in the form an electric heater incorporated into the water heater unit. The heater acts as a short-term form of freeze prevention, keeping the water within the unit from dropping below freezing temperatures.

These systems also require power at all times in order to function. If severe winter weather conditions leave your home without power, your tankless water heater will be at the mercy of the elements unless you have a generator or some other form of back-up electricity on hand. Fortunately, many tankless water heaters can be outfitted with solenoid valves that shut off and drain the water heater whenever a power outage occurs.

Built-in freeze protection systems aren't designed to permanently keep ice and frost at bay. If you live in a climate where cold temperatures and snow are regular occurrences, then you're better off with a tankless water heater that's installed inside of your home.

Your Pipes are Still Vulnerable

Keep in mind that the freeze protection system protects only the actual tankless water heater unit, not the plumbing that leads into or away from it. For these pipes, you'll need to provide your own freeze protection.

For starters, you can cover your exterior pipes with self-sealing rubber, polyethylene or fiberglass pipe wrap. This should provide enough passive insulation to protect those pipes from freezing temperatures. Insulating your hot water pipes this way not only boosts your hot water temperature by up to 4 degrees Fahrenheit, but it can also save you $8 to $12 per year, according to the U.S. Department of Energy.

For added protection against freezing winter weather, you can also wrap your plumbing with an electric heater cable. Simply wrap the heater cable around the pipe in a spiral pattern, making sure that the cable does not overlap itself or comes into close contact with another section of cable. Finish up by securing the heater cable with insulated tape or a heat-resistant tie-down.

Keep Your Unit Away from Direct Winds

Unbeknownst to many homeowners, wind direction is an important consideration when installing a tankless water heater. Direct wind exposure could lead to a "wind chill" effect that can drive down tankless water heater temperatures, placing the pipes at greater risk of freezing during cold snaps.

If you're planning to have an outdoor-mounted tankless water heater installed, you'll want to talk to your contractor about your new water heater's ideal placement. Don't forget to take average wind direction and speed into account, since you'll want to keep your new unit shielded against cold winds and the wind chill effect it brings.

If you've already installed a tankless water heater and you're currently dealing with pipes affected by wind chill, then you may want to consider installing a wind break near your unit. This can be in the form of shrubbery, decorative wood fencing or any other material, just as long as there's plenty of space left for your contractor to service the unit.

With enough preparation and foresight, your outdoor-mounted tankless water heater can easily stand up to winter duty. For more information, consider websites like