Can Water Heaters Freeze?

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

While relatively 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 designed to remain operational no matter how cold it gets outside. Still, it never hurts to take precautions if a deep freeze is in the forecast, especially if your water heater is installed outside. 

Drain the Water Heater 

Before leaving on an extended vacation this winter, consider draining the water heater to avoid a plumbing emergency while you’re away. You can also drain the tank if the power goes out to avoid potential freezing. As an added precaution, you may want to install a freeze protection solenoid valve, which opens automatically and drains the water heater during a power outage. 

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. 
  1. Flip the circuit breaker providing power to the water heater. 
  1. Connect a hose to the drain valve or place a bucket under it to catch the water. 
  1. Open the valve to start the flow of water. 
  1. Continue draining until the tank is empty, then close the valve. 

Leave the Water Running 

Consider 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 prevent frozen and burst pipes. 

Install Insulation 

Plumbing insulation comes in many forms. You can insulate your water heater tank with a special blanket to help reduce standby heat loss and provide protection against cold weather.  

Of course, pipes are more likely to freeze than water heaters. Along with running a trickle of hot water, you can protect exposed pipes located outside or along exterior walls by wrapping them in foam insulation. You can also 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 primary purpose of this system is to move hot water to the tap faster, shortening the wait time and reducing the amount of water that pours down the drain. A hot water recirculation system is convenient, water-wise and energy-efficient. It also keeps your pipes warm in the winter and makes your tankless water heater less likely to freeze. These combined benefits could justify 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 sometimes installed in the garage or even outside. While this practice is perfectly safe most of the time, the occasional deep freeze can have catastrophic effects on outdoor water heaters. For this reason, you should insist that your next water heater be installed inside, or at least in a covered location sheltered from the wind. 

Choose a Water Heater with Built-In Freeze Protection 

Most 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 option is to install it outside. 

Different brands use different freeze-prevention methods. Some have an electric element that provides just enough heat to prevent internal freezing. Others fire up the gas burners to heat a small amount of water and, in turn, keep the tankless cabinet frost-free. 

No matter the method, water heater freeze protection is only effective when turned on. First, check the unit to make sure this feature is activated. Then, for protection during a power outage, consider investing in 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 perform any water heater repair or replacement you need. We can also recommend steps to help your pipes and plumbing appliances last longer in any weather. For more information or to schedule a visit, please contact a Service Experts office near you today. 

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