A while ago, we decided to turn our central air setting to "constant fan" thinking to keep the air moving around more, and to avoid the constant loud/quiet decibel level changes. After about a day of this, I noticed an icky odor, but in only one room, so we put the fan setting back to where it only blows when the a/c kicks on.
The smell, however, hung around, even when the a/c isn't on. It has gotten slowly worse, and now when I am in that room, the smell is constant rather than intermittent and elusive as it ws at first. I can only describe it as a sort of gassy smell, like, sorry, a fart. Since we sleep in this room, I'm getting concerned about health issues.
Neither husband nor I are/am very handy, but part of the unit is in the attic, including a big pan (that appears dry) which is easily accessible, so if there's something I can check, I can do that if it's described in layman terms.
What can this be?? And how would using the constant fan setting have set it in motion?
or should we just call an HVAC company (original,1993, installer long since retired)?
Thank you in advance for any thoughts, suggestions, and help.