How do I prevent pipes from freezing in winter?

Pipes freeze when the temperature around them drops below 20°F, especially in uninsulated crawlspaces, attics, and exterior walls. The most effective prevention is keeping a steady trickle of water running from faucets on exterior walls — running water is far less likely to freeze than standing water.

Start before the first hard freeze. Drain and disconnect garden hoses, shut off outdoor spigots, and wrap exposed pipes in foam insulation sleeves (available at any hardware store for a few dollars). If you’re leaving town, set the thermostat no lower than 55°F and open cabinet doors under sinks to let warm house air reach the pipes. A pipe burst can release hundreds of gallons of water in hours, so a few minutes of preparation is cheap insurance.

If a pipe does freeze, never use an open flame to thaw it. Use a hair dryer or heating pad starting at the faucet end and working back toward the frozen section.