Periodically inspect unit for grease and soil accumulation. Clean with warm water and soap. Do not use cleaners containing ammonia. Inspect the drain pan/fan panel occasionally for proper condensate drainage. Keep the drain opening clean.
WARNING: All power must be disconnected before cleaning drain pan/fan panel. It serves as a cover of hazardous moving parts. Operation of unit without pan in place constitutes a hazard.
If drain pan has an ice build-up, drain line may be frozen. The drain line should be pitched sharply and exit cabinet as quickly as possible. Sometimes location and ambient at the drain outside of cabinet may cause freeze-up. A drain line heater may be required to correct the freezeup. Any traps in the drain line must be located in a warm ambient.
Source: MaintainX (Community Member)