Missing Secondary HVAC Drain Pan

Secondary drain pans are necessary when a furnace or air handler is installed above living space in a structure such as the attic. Primary drain pans inside the units can become clogged or leak causing moisture to penetrate the ceiling below causing water damage as well as mold. The secondary pan should either be plumbed to the exterior of the structure or have a float switch installed that shuts down the unit if the pan becomes filled with water.