JSR13
New Member
My son had some plumbing done by a plumber for his washing machine. He has gotten a new washing machine since then. Now whenever he runs it, you can hear gurgling sound and the water overflows out of top of drain pipe. It eventually drains down. All the piping is 1.5". The washer drain pipe is 24" long. There was an AAV installed directly after p-trap that is 14" long. It is then tied in to drain line for sink upstairs. The house is from 60's so it has cast iron piping that runs into floor (i think, not sure what material it is). That piping is 1.5". If I change all piping for washing machine to 2" and tie it to 1.5" drain line that it is tied in to now, will that fix the problem? Should AAV be located higher than top of drain pipe for washing machine hose? Also, no other drain in his house has a problem with backing up. Thanks.
