There are several ways to help prevent a sump pump hose from freezing in the winter including detaching the extension hose before winter, insulating the sump pump hose and making sure that the hose is properly buried underground. When burying a sump pump hose, the burial must be done away from the house's foundation to work properly and avoid freezing.
Some sump pump hoses have an extension hose that connects on the exterior of the house to the ground. This hose can be disconnected in the fall, before winter. If the house has underground extension pipes all of them must be disconnected prior to winter to prevent freezing and damage to the sump pump. Sump pump hoses that are buried underground should be buried at least 5 inches below the frost line to prevent freezing. The line can also be buried on an incline that helps to drain the hose, preventing water from collecting and freezing in the hose. Having the sump pump hose buried on a positive incline keeps the water flowing away from the foundation of the house. This also keeps the pump from having to pump the water out twice if it collects around the pump. Sump pump hoses can also be insulated with a product like heat tape to prevent freezing.