To avoid having to deal with frozen lines this winter, here are a few preventative measures to keep in mind: Insulate your pipes: Poorly insulated sewer pipes are more likely to freeze, especially in areas with harsh winter temperatures. Seal outside vents: Sealing the vents in your basement and crawl space will limit the flow of cold air around the pipes, lowering the chances of freezing. Check out your water heater: If your water heater is unable to maintain the proper water temperature, the water flowing through your pipes may end up freezing. Keep your thermostat consistent: Keeping your thermostat at a consistent temperature provides a constant circulation of warm air that may prevent costly plumbing issues.