Help! Condo condensate drain overflowing into my apartment

[FIKris]

Anyone else have problems with their HVAC condensate drain overflowing in the summer?  I live on the ground floor of an 8 story condo building.  We all have individual HVAC systems (split air-source heat pumps) in our units.  Unfortunately, they all connect to the same condensate drain pipe…which happens to enter the ground in my unit.  On hot humid days when everyone's AC is humming, all that water tends to overwhelm the condensate drain and it backs up, right into my unit.  I've had to have the floor fixed 3 times in 6 years.  Does anyone know of a solution for this?  I'd like to come to the condo board with a proposal that is better than "pay for my floor to be replaced when this happens every other year."

[Greg]

It all depends on how they are currently plumbed.  A check valve might help, or maybe a condensate drain cleaning is in order.  The best solution would be separate drains.

[guitar_stitch]

I'm pretty sure no code anywhere would permit the joining of the condensate drains due to this very risk.  That said, these systems may be grandfathered in.

I can't imagine it was always this way from day 1, so that means something has changed.

1) The drain probably has some nice mildew and crud buildup.  You can try killing that off with bleach.  (I bleach mine once per year)
2) Make sure you have some sort of trap in the line.  This may not help if #1 is a factor.

Can you provide any pictures of the drain line as it is?  There may be some routing tricks you can use to encourage better flow.

[Spork]

The way I've always seen them plumbed (and I'm not a plumber or an HVAC tech... I'm just a guy...) is this:   The normal condensate drain goes into the normal septic/sewage lines. 

To me this sounds like an overflow drain.  I.e. -- the secondary drain that an AC will take when the first path is blocked. 

It sounds like there may be more than one issue:
1) this drain is badly designed and backs into my apartment
2) something else is clogged that makes it use this drain

[zolotiyeruki]

I've had it happen to me, although not in an apartment building.  It was just a clog in the line--I think I cleared it with a long zip tie.

[FIKris]

Thanks everyone!  I'll try to get some pictures; it's a bit hard to get to because it is in a tight closet behind the washer-dryer.  I've heard from some other people in the building that the drain probably shouldn't have passed code inspection when it was renovated in the 90s…ugh.  Some people suggested bleach - I'll give that a try.  Any reason not to try drain opener, like drain-o or something?

[guitar_stitch]

1) Draino could create nasty fumes that will flow into all apartments;
2) Draino could destroy the lines, exacerbating the problem;
3) Draino is not particularly nice to the environment;

Here in Florida with our water crisis and surface water nutrient limitations, water companies really don't want you running essentially nutrient free water into their septic system.