Abstract: A cleanout fitting for air conditioner evaporator drains facilitates the mechanical cleanout and hydraulic flushing of the entire drain line from an air conditioner evaporator unit, or air handler. The present fitting essentially comprises an asymmetric T configuration, with a shutoff valve in one side of the crossmember of the T and a removable cap in the opposite end of the crossmember. The fitting is normally configured with the cap in place to block drainage therefrom, and with the valve open to permit flow from the evaporator pan through that crossmember side and out the stem of the T to an appropriate drain system. When the line becomes blocked and causes water in the evaporator pan to back up, the plug is removed, allowing a mechanical cleanout tool (snake, etc.) to be passed straight through the crossmember of the T and its open valve, to the evaporator pan.