My washing machine drain is making a sucking dripping sound which is very bothersome. (I live in a small condo.)It is a stackable washer dryer if that makes a difference. I pulled the stackable unit from the wall and put my hand over the drain where the sound is coming from. It feels like it has suction.
What seems to trigger the problem most times is my central AC unit. After it runs a while and shuts off. The sounds begin. Maybe the condensation line from the air is contributing I don't know . Any help telling me what I can do about this noise would be greatly appreciated.Thanks.

You're a tad shy of details there Jungle. Does this noise happen as the washer -- runs?-- discharges? Or when it's shut down? If it talks to you when it's not running then I would suspect the AC condensate line's discharging into the washer stand pipe. This problem will only be relieved when the AC line is removed and directed out doors. Complain to the Condo Board but don't look for much help. If it costs money Condo Boards are reluctant to pay for a repair unless it's necessary. Good luck, Tom

[QUOTE=jungle13;1777931 I pulled the stackable unit from the wall and put my hand over the drain where the sound is coming from. It feels like it has suction.
[/QUOTE]

Take a piece of toilet paper and put it over the drain when you hear the noise, if the drain sucks it in, you have some serious problems. My bet would be that you don't have a trap on the washer drian. If you did, you wouldn't hear the noise of other fixtures, or condensate of ac. Does your washer drain have a trap? Let us know.

If no trap on washer drain, your drain may be acting as a vent for other fictures in the condo.(sucking in air)