Just wondering, since I haven't seen a house in decades that had a dishwasher but didn't have a sink-drain grinder.

I have heard that connecting it this way is partly done so there's an air gap between dishwasher and drains, and I'm guessing that installing without the macerator might require a vacuum breaker or something of that sort... but I'd sorta liks to know for sure.

(My place has both, but I'd really be just as glad to jettison the macerator.)

  • A disposal is NOT a replacement for an air gap. An air gap is still needed even when a disposal is used.
    – JPhi1618
    Dec 21, 2015 at 19:09
  • Here's another question that's basically the same: diy.stackexchange.com/q/15021/43874
    – JPhi1618
    Dec 21, 2015 at 19:12

1 Answer 1


I have had several houses with a dishwasher but not a garbage disposal. I don't think it really changes the installation that much... the dishwasher waste pipe connects to the sink drain before the trap.

enter image description here

If you want to plumb the dishwasher somewhere there isn't a sink already, you need to install a trap & standpipe, similar to the way a washing machine is done.

  • Thanks for the sanity-check . If/when the disposal dies, I'm inclined to just put in pipe.
    – keshlam
    Dec 21, 2015 at 5:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.