Can Water Heaters Freeze?

Depending on where you live, mild weather or harsh cold may be the norm this winter. Either way, your water heater works harder when the temperature drops outside the house. This begs the question — can water heaters freeze?

Although very rare, it's certainly not impossible for a water heater to freeze. The biggest concern is that any standing water inside the tank or tankless unit will freeze and expand, destroying the appliance in the process. If this happens, you may have no choice but to replace the water heater.

Rest assured that water heaters are engineered to be operational regardless of how cold the weather is. Even so, it is always prudent to take safety measures if a deep freeze is in the forecast, especially if your water heater is set up outside.

Drain the Water Heater

Before leaving on an extended vacation this winter, think about draining the water heater to prevent a plumbing emergency while you’re away. You can also drain the tank if the power goes out to avoid potential freezing. For added protection, you could install a freeze protection solenoid valve, which opens instantly and drains the water heater during a power disruption.

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

1. Turn off the cold-water supply valve, gas supply valve, and temperature control knob.
2. Flip the circuit breaker delivering power to the water heater.
3. Attach a hose to the drain valve or place a bucket under it to collect the water.
4. Open the valve to create the flow of water.
5. Don't stop draining until the tank is empty, then close the valve.

Leave the Water Running

Think about leaving a trickle of hot water flowing from a faucet or two until the bitter temperature subsides. The associated increase in your utility bill is well worth averting a frozen water heater. This method also helps avoid 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 specific blanket to help reduce standby heat loss and provide protection against cold weather.

Obviously, pipes are more inclined to freeze than water heaters. Along with running a trickle of hot water, you can shield exposed pipes located outside or along exterior walls by wrapping them in foam insulation. Another option is 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 product label carefully if you plan to use them together.

Put in a Hot Water Recirculation System

The basic objective of this system is to push hot water to the tap faster, shortening the wait time and reducing the volume of water that pours down the drain. A hot water recirculation system is simple, water-wise and energy-efficient. It also keeps your pipes warm in the winter and makes your tankless water heater less susceptible to freezing. These combined benefits could validate the installation cost, particularly in cold climates.

Select a Suitable Installation Spot

Most North American homes have indoor water heaters. However, in mild southern climates, water heaters are occasionally installed in the garage or even outside. While this practice is reasonably safe in those specific climates, the rare deep freeze can have catastrophic effects on outdoor water heaters. Because of this, 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

The majority of tankless water heaters have built-in freeze protection that works in temperatures down to -22 degrees F. The next tankless water heater that you buy should have this, especially if the only choice is to install it outside.

Different brands use different freeze-prevention methods. Several have an electric element that supplies just enough heat to avoid internal freezing. Others fire up the gas burners to heat a small amount of water and, as a result, keep the tankless cabinet frost-free.

Whatever the method, water heater freeze protection is only successful when activated. First, check the unit to make sure this feature is switched on. Then, for protection during a blackout, consider purchasing 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 possibly freezing this winter, turn to Service Experts Heating & Air Conditioning. Our well-trained plumbers can accomplish any water heater repair or replacement you need. We can also suggest steps to help your pipes and plumbing appliances last longer in any weather. For more information or to arrange a visit, please contact a Service Experts office near you today.