This is the plumbing setup under our kitchen sink, there are two p-traps, one for the kitchen sink and another for the dishwasher that both feed into the drain pipe.

The black p-trap (dishwasher) which is currently broken is leaking at the p-trap. If you were to take a pot of water and dump it into the sink, the water will start leaking almost instantly out of the black p-trap (a lot of water). At first, we thought maybe a clog, so we snaked the drain (25 ft) and came up with nothing, the pipes seem clean, we can't determine why it's leaking constantly (when the water is running).

Does the drain pipe need to be pitched down more? Should we remove the additional p-trap?


  • It's leaking from the top of the back P trap, on the right, with the rag or something on it? Also, you said you snaked the drain.. did you check that the white P trap was clear of debris? – cutrightjm Jan 5 '20 at 7:30
  • You should cut and cap the pipe for the dishwasher. When you fix the dishwasher you should get a new tailpiece that has a dishwasher inlet. You also should have a vent on the black pipe. – Platinum Goose Jan 5 '20 at 13:55
  • Yes the black p-trap with the tape on it is leaking, it’s leaking at the p trap connection and sometimes will shoot out the top since it’s not capped. We checked that the p-traps were clear of debris. Also when u say vent on the black pipe, do u mean on the drain pipe? – BlackMarq20 Jan 5 '20 at 16:06
  • Yes the drain pipe that goes into the floor should be vented. – Platinum Goose Jan 5 '20 at 23:05
  • Hmm, ok at this point I might have to contact a plumber. I just checked every drain in the house and none of them have a separate air vent, there is a large pipe/vent that goes out through the roof I'm assuming they all use this one as an air vent. – BlackMarq20 Jan 6 '20 at 13:35

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