When frozen condensation builds up around the evaporator coils, it must be melted by the evaporator heater to keep the refrigeration system working properly. The first stop of the condensation once it has been melted is the evaporator drain trough. This trough collects water and helps funnel it to its final destination in the condensate drain pan at the bottom of the unit. Don't let a broken evaporator drain trough cause a leak in your unit. Order a new one today!