I've recently noticed a gas like odor as I walk by my dual a/c and furnace unit in my basement. I only really notice it when the ac is running or right after. The smell reminds me of natural gas but I had my gas company come out and they checked all the pipes and air and everything checked out. I also have explosive gas and carbon monoxide detectors right by the unit and on all floors so sounds like I'm safe there. Even weirder is that I only smell as I walk by the unit. If I stop I can't identify the smell. I checked the A coil and although rusty and water looks to be slightly built up, I didn't see any mold or mildew. I was thinking possibly freon but would expect to smell that all the time and I read it's odorless. Also checked my floor drains to make sure the trap wasn't empty. The a/c unit works fine and no smells from the actual vents so I'm starting to think I'm just worrying over nothing or its in my head. Unit is about 14 years old. Any ideas?

i have a mini-split ac. the indoor unit started to leak water because the drain pipe is clogged. i detached the drain pipe from the unit and tried to unclog it with a blower and a vacuum machine several times. but still the water would not go in. i can't access the other end of the pipe because it goes within the wall to the house's drainage system. i don't know what to do now. years ago i had the same problem with an older unit, the technician suggested i drill thru the wall and put a new drain pipe where it drains water to the outside of the house but i don't want that. any suggestions? I'm thinking of putting some drain opening powder & bleach on the drain plate, but could this be dangerous and ruin the indoor unit?