Can Water Heaters Freeze?

Dependent upon where you live, mild weather or severe cold may be ordinary during the winter months. Regardless, your water heater works harder when the temperature drops outside the house. This makes many people ask the question — can water heaters freeze?

While relatively rare, it's definitely not impossible for a water heater to freeze. The primary concern is that any standing water on the inside of the tank or tankless unit will freeze and expand, ruining the appliance along the way. If this happens, you may have no choice but to replace the water heater.

Today's water heaters are built to remain operational regardless of how cold the temperature drops. Even so, it is always prudent to take safeguards if bitter cold temps are heading your way, even more so if your water heater is set up outside.

Drain the Water Heater

Before departing on an extended trip this winter, think about bleeding out the water heater to avoid a plumbing crisis while you’re away. You can also drain the tank if the power goes out to avoid potential freezing. As an added precaution, you might choose to install a freeze protection solenoid valve, which opens automatically and drains the water heater during a power failure.

Here’s how to drain a water heater tank by hand:

  1. Shut off the cold-water supply valve, gas supply valve, and temperature control knob.
  2. Flip the circuit breaker supplying electricity to the water heater.
  3. Fasten a hose to the drain valve or place a bucket beneath it to collect the water.
  4. Open the valve to start the flow of water.
  5. Continue draining until the tank is empty, then close the valve.

Leave the Water Running

Give some thought to leaving a trickle of hot water flowing from a faucet or two until the cold snap subsides. The resulting slight increase in your water bill is well worth avoiding a frozen water heater. This method also helps reduce the risk of frozen and burst pipes.

Install Insulation

Plumbing insulation is very affordable and comes in a variety of forms. You can insulate your water heater tank with a special blanket to help cut down on standby heat loss and deliver protection against cold weather.

Not surprisingly, pipes are more inclined to freeze than water heaters. Beyond running a trickle of hot water, you can protect exposed pipes situated outside or along exterior walls by wrapping them in foam insulation. It's also possible to install electric heat tape to keep the pipes just above freezing. Only some types of heat tape are compatible with insulation, so read the directions for use carefully if you plan to use them together.

Put in a Hot Water Recirculation System

The basic objective of this system is to move hot water to the tap quicker, decreasing the wait time and reducing the amount of water that is wasted down the drain. A hot water recirculation system is convenient, water-wise and energy-efficient. It also warms the pipes during the cold months and makes your tankless water heater less prone to freezing. These paired benefits could validate the installation cost, especially in cold climates.

Choose a Suitable Installation Spot

Most North American households have indoor water heaters. However, in mild southern climates, water heaters are occasionally installed in the garage or even outside. While this practice is perfectly safe most of the time, the unexpected deep freeze can have negative effects on outdoor water heaters. For this reason, you should demand that your next water heater be installed inside, or at minimum in a covered location sheltered from the wind.

Choose a Water Heater with Built-In Freeze Protection

A large number of tankless water heaters have built-in freeze protection that works in temperatures down to -22 degrees F. Make sure your next water heater has this feature, especially if the only choice is to install it outside.

Different products use different freeze-prevention methods. Several have an electric element that yields a sufficient amount of heat to avoid internal freezing. Others spark the gas burners to warm a small amount of water and, in short, keep the tankless cabinet frost-free.

Regardless of the method, water heater freeze protection is only helpful when activated. First, check the unit to make sure this feature is engaged. Then, for protection during a power failure, consider buying a small portable generator, whole-home standby generator, or battery backup power supply for your tankless water heater.

Schedule Water Heater Services

For answers to questions about your pipes or water heater potentially freezing this winter, turn to Service Experts Heating & Air Conditioning. Our well-trained plumbers can complete any water heater repair or replacement you need. We can also propose steps to help your pipes and plumbing appliances last longer in any weather. For more information or to plan a visit, please contact a Service Experts office near you today.