Our washer is in the kitchen and when it drains, it fills the bathroom sink before it goes into the main drain. We have always had this problem. I'm about to buy a new laundry center that has a front load washer that uses less water and may output the water at a slower rate. How can I fix this problem before I install the new washer? I have heard about some sort of valve that would make the water go down after it hits the bathroom and not into the sink. Can anyone help? Thanks, Wes:(

Hi Wes:

Most likely that new machine will have an increased volume of flow out of washing machine. New machines not only use less water but their pumps are more powerful and discharge at greater volume then old machines... so, may have even bigger issue then you have already.

The washing machine has its own drain line (p-trap and standpipe and vent)... right? And even with own piping, still backs up into lavatory sink.. huh? Can you tell me how large the drain pipe is and what material piping/fittings are (pvc, galvanized metal, copper pipe, cast iron)?

They do make a backwater valve, but I don't think this will work for you. My gut feeling is that the drain line is clogged and needs to be snaked out. Even if drain drains, does not mean it is clear drain line... here, when volume exceeds capacity of pipe, will back up to nearest drain if it can... why I am going for clogged drain right now or that th epipe is too small and connected to closely to the bathroom sink

Ideally, washing machine will have a 2" drain line, 2" ptrap and 1.5" vent with a 24-30" standpipe out of ptrap... let us know what yours is.. if even present??

See if you can answer all my questions... then I will can figure out best answer to this... talk soon... Mark

The washer is in the kitchen, the drain is in the wall between the faucets. I think it's 1 5/8" galvanized pipe. That goes down and through the house back to where it meets the bathroom sink. The sink and the washer drain into the same pipe. When the washer drains it fills up the bathroom sink i assume because the output is too great for the pipe size. But the manual for the new washer says it only needs a 1 1/4" pipe that can drain 17 gpm. Maybe we need to create a new drain with pvc next to the washer, out through the wall and into the backyard with a 2" pipe? Thanks, Wes

No... no draining into yard... Ok? Are you on a slab house? If not, pipes in basement should accommodate increase in drain size..?

The pipe that goes into floor should be a 2" drain pipe. That is enough to handle discharge from washer...confirm if possible where WM drain joins sink and goes into ground (may just increase before entering ground...but should increase to 2").

I am still arguing partial drain blockage until you confirm that combined washer/sink drain pipe is only 1.5" into basement or underground... ok? ;) .

Get back.. let me know thoughts.

.

Lol, OK, It is a slab foundation, one story, circa 1960. I measured the pipe for the washer drain, it's 1 1/2 ". I think the bathroom sink and the washer drain come together under the bathroom sink and then go down into the main drain. I will have a plumber come and see if it needs snaked tomorrow.