FYI: Had a puddle of water under the home ac unit in a closet. They have two drain ports the lower one is piped the slightly higher emergency one just dumps on the floor then into the crawlspace. Somehow the piped drain line was not taking all the condensate. There were rust stains around the emergency drain port when we bought the house.
They had duct taped the vent tee for the drain which may have been an issue. Two 90 degrees bends so no easy way to snake it out. Today wife poured one gallon of water into the drain vent and I watched it come out the drain pipe outside the foundation. It had rust and some bits of crud. Maybe dead bugs?
I will replumb using tees, flex pvc conduit and plugs instead of elbows so it can be cleaned.
Bil lD.

It is coming up on time to clean the drain tubes on the car sunroof