Why Do Pipes Freeze in Homes With Heat?

Your home's heating system warms the air in living spaces, but that warmth may not extend to all the plumbing. Pipes running through exterior walls, garages, or basements are often outside the heated envelope. These locations can be dozens of degrees colder than your thermostat reading. A small gap in insulation or a crack letting in cold air is enough to put a pipe at risk. You might not even realize how cold these spaces get until a freeze occurs.

Lowering your thermostat at night or when away saves energy, but it also reduces heat flow to vulnerable pipes. The air in unheated cavities cools faster than the main living area. If you lower the heat, pay extra attention to pipes in those cold spots. A sudden cold snap can surprise homeowners, making consistent vigilance and pipe insulation crucial during winter months. Consider the specific layout of your plumbing when setting your thermostat for extended absences.

Prevention focuses on getting heat to cold spots and keeping cold air out. Insulate pipes in attics, crawl spaces, and garages with foam sleeves. Seal cracks and holes in walls where pipes enter. Let warm air circulate by opening cabinet doors under sinks on cold nights. For pipes in extremely cold areas, consider installing heat tape according to the manufacturer's instructions. An annual inspection before winter can help you identify new vulnerabilities.

• Insulate all accessible pipes in unheated areas.
• Seal air leaks in walls, floors, and foundations.
• Keep garage doors closed during freezing weather.
• Let faucets drip slowly to keep water moving.
• Open cabinet doors to let room heat reach pipes.
• Identify and know how to operate your main shutoff valve.