An anti-clogging liquid dispersion system and method for an air conditioner or heat pump is disclosed. A tank holds an anti-clogging liquid. A pump or valve connected with the tank periodically supplies the liquid to a condensate drain pan or the outlet of an existing drain line located exteriorly of a structure. One or more sensors are provided to detect moisture, flooding and/or lack of condensate flow and, when so detected, a control circuit causes the liquid to be supplied to the condensate drain pan to prevent flooding of a condensate drain pan or to clear a clogged drain line of an air handler of the air conditioner or heat pump. An additional dose of the liquid can also be supplied at any time when an unacceptable amount of condensate moisture and/or a clogged drain line has been detected.