Yesterday my air conditioner condensate pipe was leaking. My repairman cleaned the pipe and said it was clogged by dust from the air duct, and tried to bill me for cleaning it out. I want to appeal because my air conditioner had its annual checkup less than two months ago. At that time, the repairman said he cleaned the pipe out and the dust had built up in just two months. Is it reasonable that my condensate pipe had gotten clogged in just two months? Thanks.

More likely Algae, as the condensate pipe has a vacuum on it. When there is no water in the pipe, you can feel air being drawn in as the air handler is drawing air in. once there is water in the trap it stops drawing in. Bleach in drain pipe helps. Sounds like it clogged and overflowed. They make a float that goes on drain line, if unit clogs, water backs up float rises and shuts down AC to stop it from making water(Leaking water everywhere). He may not have cleaned it last time?