Guys, I need some help or suggestions on how to handle this. One of my stores had a roof leak from about a 15 yr old York RTU. During last storm, I traced leak and found it to be a knockout in bottom of rtu gas firing (combustion) area. There was a hole about 1.5" in diameter with a plastic plug pushed into sheetmetal. This hole looked to be either for conduit or gas line. Anyhow, I used foam and sealed the area up.
I have another leak from another unit (same size) that is very similar. I found it to be leaking into the ceiling from what looks like a piece of pvc that is also around 1.5" in diameter and running about 6" down from flooring of rtu sd into ceiling cavity. This pvc "stub" appears to have a plug in the end of it. I can't reach it from the inside, as it is too high up in roof. I can't get to it from inside of rtu because it is about 3' from curb and directly inline with evaporator coil/condensate drain tray. All I can see is what looks like white caulking under the evap that is directly inline with where the leak is coming from. I am wondering if this is supposed to be something like an alternate condensate drain, where it could drain thru roof instead of onto roof from piping at end of tray.
Can anyone give me any insight on how to seal this without having to pull the evap coil? Thanks.