I posted this scenario in dirty sock syndrome, but fact is I don't have a clue. We are in a 16 month old house (second winter) and have been experiencing a musty smell from our return air after we take a shower. The system is a Lennox, but I do not think it has a heat pump. The smell is in no other room except the hallyway where the return air is located. I have had a plumber check the ventilation pipes for cracks, etc., leak pressure test on the water lines, duct camera inspection for mold in the ducts, and air condtioner guys out to check system out. All have no answers. When the duct service man came out, he said our attic did not smell normal so I am in the process of having the insualtion checked. Personally I have been in the attic and this does not smell like the musty smell in the return air. My duct person has suggested a duct pressure test, but I feel this does not solve my odor problem. He did say our house seems to acting under negative pressure because some of our doors will close when the unit is running and when it is off there is a small draft coming down from the return duct. HELP!!!
[Edited by charlezz on 01-26-2006 at 01:08 AM]