
AC Smells Musty or Moldy: Why It Happens and How to Get Rid of It
why does my AC smell musty or moldy almost always comes down to trapped moisture — a system running nonstop against Arizona’s 110–115°F heat keeps the evaporator coil cold and damp, and that moisture feeds mold, mildew, and bacteria on the coil, in the drain line, and inside the ductwork.

