Prepaid maintenance on three carrier heat pump split systems. Found on both downstairs units heavy corrosion in the evaporator coil also water damage to the insulation and microbial growth inside of the air handler. Went over these issues with the homeowner they are going to think about it and get back to us. Due to age condition and overall efficiency recommending replacement on the two downstairs units. The upstairs unit is the same age but in much better condition. The evaporator coil has a little bit of corrosion but it’s just surface. System is working well no action is needed at this time.