I moved into a upstairs apartment- studio 425 sq feet. The building is a 2 story building. It was built in 1971.

There is a horrible foul smell from my central AC. When it is not running and with windows open, I can smell it from the AC closet that it sits in. When the AC runs, my apartment will randomly smell horrible. Even my clothes will absorb the smell and I can smell that foul smell at work.

The drainage tube connects my AC with my neighbors downstairs. It has a T pipe and I can pour Clorox in it. If I pour a cup of Clorox down in it every few hours, it rids the foul smell. But it also makes my apartment smell like Clorox and I am not sure if that is healthy. If don't pour Clorox in it...the foul odor comes back with in about 9 hours.

I thought at first the AC coil was dirty, but if I am able to get rid of the smell with Clorox in the drainage tube then I don't know what is going. Can anyone please tell me what is going on with the AC? I'm not getting any help from the landlord.

  • 2
    Are you sure the Clorox is getting rid of the smell and not just masking it?
    – mikeazo
    Aug 23, 2017 at 0:51

2 Answers 2


The condensate drain line at your unit should have a trap built into it to keep sewer gasses from being pulled up that line. Opening a window may worsen the problem. Since you live in an apartment, I would have a licensed HVAC company do the work. You could then contact the apartment manager for a refund. You could also contact the housing authority for advice on how to rectify the problem. Other solutions may be justified such as a small condensate pump to handle the condensate from your unit only. If you are handy, they cost around $40.00 dollars from "amazon ", or just have the previously mentioned professional do the work.


I finally caught the AC leaking water down into the air take(through the air filter in the middle). It doesn't happen consistently, though. The wood holding up the AC was wet also.

Would this of caused the smell? I can not imagine wet wood creating such a bad smell.

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