I have a Trane XE90 power fan assisted exhaust furnace. I noticed that condinsate water is collecting in what appears to be the heat chamber and dripping down into the fan box. I have checked the condinsate drain on the exhaust fan and note that it is open and draining as well as all of the other drains. The furnace is an updraft unit located in the basement in an open finished 12 x 9 room. The furnace is not enclosed but exposed to the open room. There is currently no door on the furnace room but I do plan to hang one. The rest of the basement area has been finished and is partitioned off from this room.
The powered exhaust pipe is PVC that runs up at a 45 degree angle to the ceiling height and then runs horizontal out the side wall. I checked the exhaust outlet and confirmed that it is exhausting with powered force. There is no fresh outside air piped into this area. The furnace instructions do not call out for any. The furnace was installed at the time the house was built in 1998.
What is causing this condinsate? This will rust my unit out. I have just finished off the basement area into living area and did not notice this condition before. I have tried to get some support from Trane Co. but have only been blown off. What is your ideas on this issue?