I investigated the rust spot on the emergency drain pan on both units and performed a general check on both. I could not locate the furnace model and serial numbers. I discovered that the TXV insulation was not installed on either systems. There was a loose clamp in the furnace causing water to drip. I tightened it. I located the insulation in the attic and installed one of them. The other was destroyed where I could not use it. I discovered that the flue pipes and fresh are are piped backwards. This is a hazard, would reduce heating efficiency, and cause the system to trip on high limit easily. The emergency pans on both systems are 2 pans that aren’t sloped correctly. We will need to get an insulation for the TXV, swap the vents on both systems, and replace the emergency pans with 60x32 pans. The drain is located on 60 side. This will also cause us to adjust the drains accordingly. Customer is selling the home and plans on reaching out to the builder.