I hope someone here might be able to help me. I have lived in my house for almost 3 years now and it is a new house. Within the last 2-3 weeks soap suds have begun backing up out of the washing machine drain in the wall. You can run just water and there will be no drain problem at all. We have tried different brands of soap and different amounts. The overflow of suds occurs when the machine is pumping out any remaining water before the rinse cycle and spin cycle. When it pumps mainly water it flows fine, but when it pumps very little water and mostly air is when the suds come up. I called several appliance repairmen that I know and they all thought that the drain line might be clogged. My plummer came out and ran a 6' snake through the drain and a 75' through the cleanout. He said he really didn't feel anything and thought it was clear. Low and behold it foamed up again. I traced the roof vent line for the washing machine and ran the water from the hose down the vent (don't know if that was bad to do or not, but no leaks in the vent). It drained fine, so I do not think it was clogged. Ran the machine again and suds came out. I cut the sheet rock and found that I have a 2" drain line about 24" long from the top of the drain to the bottom of the p-trap. From the p-trap it angles up and over to a 2" vertical pipe. At this connection there is a 1-1/2" vent above the fitting and a 2" drain pipe below the fitting that goes down into the slab. About 4" below this fitting there is a laundry room wall cleanout. I estimate the length of the vent pipe to be about 24' to the roof. with a 45 degree fitting to go around a rafter at about 10'. I could lower the p-trap to be around 34" long, but I would have to put the cleanout above the p-trap level. Would that be bad to do and do you think by adding 8" to 10" of length might solve the suds problem? The one thing that has bothered both the plumber and myself is that this happened all the time at my last house (which was also a new house) but never at the house we rented before that. I was concerned when we moved into this house but I did not have a problem till now. I will try and insert a picture here but if it doesn't work, I can email a picture of the pipes if that will help. If its not the plumbing, then does anyone know a good appliance repair website that may know what is wrong with my washing machine?
Thanks in advance.