So we have been in our slab house how for 3 years and just noticed that we are getting water underneath out dining room floor. Come to find out it is coming from our AC unit.
While running, condensation is escaping from over the rear wall of the drain pan, being blown out through the gap between the coil box and air handler and finally running down the exterior of the air handler.
This is would be considered a blow-through or positive pressure system, since the A-coil is above the air handler. So the drain line for the condensate pan is just gravity fed (no traps, vents or clean outs) with a vinyl hose to a sewer drain.
I am just absolutely baffled as to how to keep the condensation from being blown over the walls of the drain pan. It is almost like there is a negative pressure inside the A-coil box.
Someone please help!