Laundry Dain Pipe Back up: UPDATE
There is a verticle pipe next to the laundry "rinse pipe" (or standpipe I think it's also called) with a black cap on it. Last night my husband wiped off a thick layer of dust to reveal that the cap says "Air Vent". Is doesn't seem to me like too much air is venting if there was a thick layer of dust on it. Also, is it common to have an air vent not venting "out" somewhere... just into the air of the house? I'm sure I'm just not understanding the mechanics of it.
The helpful people who posted to my original question (posted yesterday, same title) said all the gurgling in the kitchen sink and back up of water out the rinse pipe suggested a vent problem, or a clog.
Do these air vent caps need to be adjusted or replaced? My guess is that the cap is probably a good 15 or 20 years old. I have doubts that the cap is doing it's job based on the gurgling sounds in my kitchen sinks when the laundry rinses, and the water back up we experience if the kitchen sink is plugged.
Thank you so much for all the help... it really has been fun trying to get to the bottom of this and learning a little something about a subject I know nothing about in the process!