Heat tape should be installed along susceptible water pipes according to the manufacturer's direction, either ran alongside the pipe or wrapped around it as indicated. Heat tape can be held in place with electrical tape and covered with insulation or pipe jacketing, and must be plugged into a GFCI outlet.
Care should be taken when selecting heat tape, because some types are not suitable for PVC piping and can cause water damage and fires when used incorrectly. Self-regulating heat tape can adjust its heat output according to the outside temperature, and it is a good choice for pipes that may be damaged by high heat. In addition, some forms of heat tape can be cut to whatever length is needed, while others cannot be trimmed without damaging the wiring and creating the possibility of fire.
In most cases, heat tape should never cross itself. Some types of heat tape can short-circuit when crossed, causing the wiring to overheat and potentially start a fire. In addition, bending heat tape into a 90 degree angle may cause it to fail. Heat tape should never be plugged into an extension cord, as this can promote overheating and reduce the protection offered by a ground fault circuit interrupter. Once installed, heat tape should be checked at least once a year for cracks in the insulation or other signs of wear.