Called out today to perform a precision tune up on four units. Checked all electronics and motor components to ensure equipment is operating within manufacture specifications. Checked and replaced all filters and cleared drain lines. Measured the temperature drop and rise across the coils. The farthest unit in the air handler emergency drain pan is completely rusted out. Made client aware of its condition and the fact that it could deep through onto the ceiling. The guest house UV bulb is out and the coil is rusting and condensation into the drain line. Outside I removed the fans from the condensers and cleaned the coils. I noticed that the contactors were heavily pitted outside. Armaflex is rotted and falling off of both carrier condenser units. Replaced three contactors, Armaflex, and renewed maintenance agreement. Equipment is operating properly at this time. Thank you for always choosing Total Air