Installing heat tape is the best way to assure water lines in exterior walls or unheated portions of your home do not freeze during frigid weather. Most heat tapes are designed to run flat along the bottom of water lines. Wrapping heat tape around the pipe can cause shorts in the tape or worse. Refer to the manufacturer’s instructions before proceeding.
Step 1: Heat tapes should only be installed on water lines. Do not install heat tape on drain lines or pipes that are not constantly filled with water. Plastic pipes should be wrapped with foil before attaching heat tape to increase the tape’s effectiveness and reduce risk.
Step 2: Position the sensor portion of the heat tape at the coldest end of the pipe. The sensor remains on as long as power is being supplied to the tape. When temperatures drop below 40 degrees, the sensor will turn the tape on to heat the pipes and keep them from freezing.
Step 3: Secure the heat tape along the bottom of the water line with heat application tape or a good-quality electrical tape. Make sure the adhesive tape has a maximum temperature rating of at least 176 degrees.
Step 4: To be effective, the heat tape must run unobstructed along the full length of the water line. Avoid placing anything, other than foil, between the pipe and the heat tape. When using multiple tapes, leave no more than a 3-inch gap between tape ends. Anything more than 3 inches will compromise the effectiveness of the tape.
Step 5: Once the tape has been installed, wrap the pipe with 1/2-inch-thick fiberglass insulation. Do not use closed cell foam insulation or other flammable materials to wrap the pipe. Cover the pipe completely with insulation, allowing no more than 1/2-inch overlap along the way. Too much insulation can cause the tape to overheat and create a fire hazard.
Step 6: Once insulated, wrap the pipe with a vapor barrier such as plastic sheeting or foil.
Step 7: If possible, plug the heat tape into a GFI outlet. It is relatively easy to replace a grounded or nongrounded outlet with a ground fault interrupting outlet.
Check your heat tape regularly to assure it is working properly. In the spring, unplug the tape or turn off the power supply to its outlet, and make a note to turn it back on each winter.