ISU Extension and Outreach
Field Agricultural Engineer
A recurring challenge every winter in Iowa is keeping the water you use from freezing. Keeping water thawed requires adequate heat to keep the temperature of the water above freezing. The three most common approaches are adding heat with a heating device, insulating to conserve heat, and adding heat by bringing in warmer water.
Any water lines that can be emptied for the winter (sprinkler lines, empty buildings, pasture water lines, garden hoses, etc.) should be disconnected and drained. Compressed air can help remove water from some low spots that cannot be drained by gravity. Remember to remove garden hoses from hydrants and outside faucets on your home. Connected hoses can trap water and cause freezing even in faucets designed to be freeze-proof.
Household water pipes in exterior walls can freeze in extreme weather. Make sure there is sufficient insulation between the outside of the wall and the water pipes. Removing insulation between the inside room and the pipes can let more room heat get to the water line. Even leaving doors ajar on the cabinet under the kitchen sink can allow a little extra room heat in to keep pipes warmer. In extreme cases, letting a trickle of water run all night will constantly replace the cold water in the pipes with warmer fresh water.
Water pipes in unheated locations may need extra added heat. In a small enclosed space like a well pit or pump house, a small electric heater or heat lamp may be sufficient. For $20 to $30 you can even add a thermostatic plug adapter to turn the heat source off when it isn't needed. Be sure to keep heating devices a safe distance from flammable objects. Adding insulation to the pump house or well pit cover can help conserve the heat that is already present.
In more open areas like unheated buildings or crawl spaces, you may need to localize the added heat. Long strips of electrical resistance heating cable (heat tape) can be applied directly to the pipe. Some heat tapes include built-in thermostats to turn them off in warmer weather. Follow the manufacturer's instructions when installing heat tape. Never apply heat tape over itself (double wrapping) or over or under pipe insulation unless specifically recommended by the manufacturer.
Even buried, underground water pipes can be subject to freezing. Problems usually arise when soil in new water line trenches has not fully settled, or when earthwork or construction above the pipeline removes too much soil or replaces soil with materials like concrete that conduct ground heat away more easily. If you have a buried water line that is at risk because of fresh backfill or thin cover, you can add insulation on top of the ground in the form of hay, leaves, or even snow piled over the water line. In extreme cases, letting a small flow of water run continuously through the pipe can supply enough heat to keep a line open. With buried lines, remember that the risk period may last for days or even weeks beyond the extreme cold weather until ground heat from below can migrate back up to the water line.
Livestock water tanks can be difficult to keep thawed. If electricity is available, submersible electric trough, tank, and bucket heaters can help, and are available for $20 to $50. For safe operation, use a power supply with a third wire ground. A ground fault circuit interrupter provides additional electrical safety. If electricity is not available, liquid propane gas (LPG) stock tank heaters are available for around $600. These units feature a small propane burner inside a vented submersible metal pipe. Constant flow water tanks add heat with the continuous flow of warmer supply water. An adequate drain must be provided for the overflow water to prevent mud and ice around the tank.
Energy-free waterers are available for new installations. These waterers utilize ground heat from below and extra insulation to keep water warm. If properly installed and adjusted, they work well in all but the worst Iowa conditions. Expect to pay about $100 more for energy-free waterers than for electrically heated models. Adding insulation to the outside of a water tank and even to the water surface can help conserve heat. When adding insulation, be sure to protect the insulation from animal chewing, manure, and spilled water.
For small quantities of water, electrically heated buckets and water dishes are available for $30-$100. Make sure these units are properly grounded and add a ground fault circuit interrupter for additional safety.