The condensate drain from our air handler now runs across the wall and into the laundry sink. This is stopping us from attaching shelving to the wall. I noticed that the sump pump pit is right next to the air handler. Can I just route the pvc so it empties out directly into the sump? There is a metal cover on it now with a little gap for the power cord so I would need to make another little hole for the pvc pipe and just run it down the wall then along the wall for a foot or so with a little bit of a downslope.

  • Where are you? The only possible reason it would be an issue is if there's a legal problem with doing so - it's certainly not going to break anything. Any my air handler has always been setup that way. Commented Jun 1, 2014 at 20:46
  • I am in Maryland
    – Aaron
    Commented Jun 1, 2014 at 21:03
  • Another solution would be to notch the backs of the shelves so there's space for the drain to run behind them, or to extend/reroute the drain do it comes down alongside the shelves...
    – keshlam
    Commented Jun 2, 2014 at 2:05
  • The problem is that in order to get to the laundry sink it has to go across the shelves. I don't have a lot of vertical drop to play with. However, we're going to do the closet track system, and it occurs to me that we might be able to put the vertical standards against the wall, and then just put the PVC across the standards right in front of them, with possibly a couple of elbows to just make sure that we don't bend it too much.
    – Aaron
    Commented Jun 2, 2014 at 14:46

6 Answers 6


Well, i don't really see an issue with this since the condensate water is basically distilled water with neutral PH. The legal issue with it may be due to furnace condensate water which contains carbonic acid. Using a neutralizer will take away almost all the acidity, however some municipalities still don't allow either condensate water to be piped to the sump to account for idiocy.

One possible solution, you can get a condensate pump, and have it pump the water though a tube to any sink, or drain you can run the tube to. The only downside is the sound of the pump turning on ever now and then.


Can I just route the pvc so it empties out directly into the sump?

I hear that this is a code violation in Massachusetts although I'm not 100% sure why. It may be:

  • Condensate can be mildly acidic which can eat away at metal fittings on the sump pump. However, any sort of liquid in the sump should dilute this.
  • People worry that the sump pump might freeze if it is triggered on in the winter although there shouldn't be condensate in the winter.
  • People wonder if it makes no sense to have the sump evaporating into the house and the condensate output leading to the sump.

My furnace uses condensate pump to support my self-cleaning humidifier which may support the sump freezing case because it does run in the winter. I've had to engineer a flow back system to stop it from freezing. I have some portion of the pump output going to a T and back to itself which causes the line to empty after the pump stops. Seems to work well.

  • 1
    The condensate from a furnace or boiler is the result of combustion and so can be acidic. But condensate from an HVAC air handler (cooling coil) or air conditioner is just plain water extracted right from the air. Commented May 23, 2020 at 14:47

If it were my home I would just do it. If there is some 'code' that disallows it I would sure like to hear the logic behind it.

  • Code may not require it, but might you want an air gap between the condensate drain pipe and any possible standing water in the sump? I wonder if there are any conditions where there might be even moderate suction acting on the drain pipe.
    – Grunthos
    Commented Jun 2, 2014 at 20:38
  • Not if it has a trap, as it should. @Grunthos
    – Mazura
    Commented Oct 1, 2014 at 7:27

I don't think there is anything wrong with this, but a downside to this approach is that your sump pump will run a tiny bit more, consuming electricity and producing noise.


Not only is it okay to drain it into the sump, in many localities it is against code to drain it into a sink (or anything else that connects to the sewers).


I would not pipe condensate in the sump pump. It will make your sump pump turn on in the winter. The water will freeze at 32degrees where people will slip on especially if it discharges into the Driveway or street.

  • 1
    Hello, and welcome to Stack Exchange. Do people use their air conditioners when it's below freezing outside? Commented Dec 22, 2016 at 13:02
  • Since sump pumps are often well below the frost line nothing stops them from running in the winter. It is always wise to design the discharge to handle freezing conditions outside.
    – mfarver
    Commented Nov 21, 2018 at 3:49
  • I don't think AC condensate is likely to accumulate at all during cold months. Furnace / boiler - different story/ Commented May 23, 2020 at 14:48

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