Washer drain backup

[jwhunt100]

Thanks for taking the time to read this post. I am currently having a problem with the laundry drain in our utility room. Our house was built in 1979 and we have occupied it for the last three years. Talking to our neighbors, they also experience problems with the floor drain backing up when the washing machine enters the rinse cycle. When we first moved in, the floor drain would back up and form a two-three foot diameter puddle in the floor. Recently, the standpipe behind the washer is starting to overflow as well. I have been using some drain opener and “suds dissolver” to help remove any blockage from the pipes. This works for a couple of weeks and then the problem will reappear.

My question is this; do you feel it would hurt the washing machine if I adjusted the drain flowrate into the standpipe (by installing a smaller drain line or small piece of pvc on the discharge hose itself)? I am trying to locate the owner’s manual to see if there is a valve that can be adjusted to do this as well. (It is a Sear’s Kenmore model)

If anyone has had any experience with a similar problem and managed to solve it without having to have the drainpipes lanced, please let me know.

Thanks again for your time!

[LazyPup]

I would not recommend downsizing the line.

Washing machines do not have a liquid sensor to determine when to stop the pump, instead they work on a theoretical time factor which is determined by the GPM flow rate of the pump.

Downsizing a line by merely one nominal trade size will reduce the volume by approximately 1/2 which means it would then take twice as long to pump the water out but the alloted time for pumping is predetermined by your timer design so if you downsize it may not be able to pump all the water out on each cycle.

One of the basic problems you are confronted with is that you house was built in the late 70's when the standard size for a laundry standpipe was still 1-1/2".

During the mid 1980's they began using a high volume pump on washing machines and as a consequence the code now requires laundry standpipes to be 2".

You may continue to use the 1-1/2" standpipe because it met code at the time of installation, however you must keep in mind that your standpipe is critically sized so even a minor clog in the line will cause the type of problem you are encountering.