Washing Machines drain

[cindys0417il]

Yesterday I noticed when I washed clothes and when the clothes were done..I noticed that the water in my toilet was down to almost nothing...I flushed the toilet and its fine and didn't notice water going out again...why would this happen? It only happened when I washed clothes..Never noticed this before..

[Steve S.]

Sounds like your drain vent may be partially clogged/blocked. When the washing machine drains it is syphoning the water out of the toilet P-trap. This probably also accounts for the sewer gas smell in your next question, since the reason for p-traps is to block sewer gases from entering the home. Whenever a large amount of water is drained, air in the drain pipe is also removed and must be replaced with air from the roof vent.

[cindys0417il]

Steve,
That makes sense...Thank you so much for explaining. ..so I need to check the drain vent for the clog. Thanks for your response.

Cindy