From the Texas Department of Insurance

Texas weather can change quickly, especially in the winter. A fast-moving cold front can cause temperatures to drop below freezing within hours. Outdoor pipes, pipes in unheated areas, and pipes that run along uninsulated exterior walls can burst if the water in them freezes and expands. This can shatter pipe seals or the pipes themselves, sending water pouring through your house. You can avoid thousands of dollars of damage to your walls, ceilings, carpets, and furniture by taking a few simple measures to protect your home.

Before the Freeze
• Protect faucets, outdoor pipes, and exposed pipes in unheated areas by wrapping them with rags, newspaper, trash bags, or plastic foam.
• Insulate your outdoor water meter box and be sure its lid is on tight.
• Cover any vents around your home’s foundation.
• Drain and store water hoses indoors.
• Protect outdoor electrical pumps.
• Drain swimming pool circulation systems or keep the pump motor running. (Run the pump motor only in a short freeze. Running the motor for long periods could damage it.)
• Drain water sprinkler supply lines.
• Open the cabinets under sinks in your kitchen and bathrooms to allow heated indoor air to circulate around the water pipes.
• Set your thermostat at a minimum temperature of 55 degrees, especially when you’re gone for the day or away for an extended period.
• Let indoor faucets drip; it isn't necessary to run a stream of water.
• Make sure you know where your home’s shut-off valve is and how to turn it on and off.
• If you leave town, consider turning off your water at the shut-off valve while faucets are running to drain your pipes. Make sure you turn the faucets off before you turn the shut-off valve back on.
• If you drain your pipes, contact your electric or gas utility company for instructions on protecting your water heater.

If Your Pipes Freeze
• If a pipe bursts and floods your home, turn the water off at the shut-off valve. Call a plumber for help if you can’t find the broken pipe or if it’s inaccessible. Don’t turn the water back on until the pipe has been repaired.
• If the pipe hasn’t burst, thaw it out with an electric heating pad, hair dryer, portable space heater, or towel soaked with hot water. Apply heat by slowly moving the heat source toward the coldest spot on the pipe. Never concentrate heat in one spot because cracking ice can shatter a pipe. Turn the faucet on and let it run until the pipe is thawed and water pressure returns to normal.
• Don’t use a blowtorch or other open-flame device. They are fire risks and carbon monoxide exposure risks.