I just bought a house, and I went to hook up the washer and dryer, and let me add that the utility room is in the basement fully underground. I ran the washer through a trial run and as the water was draining I noticed water coming from under the machine. After further review of the area I noticed that there is a large drain in the floor, about 3" wide going straight down to who knows where, this is where my backup was coming out of. The actul washer drain is a pvc tube coming from the wall like normal, so as the water goes into the normal drain it overflows out the floor. I have tried to snake the drain in the floor, and could not find any other opening, so that did not work. I assume both drains lead to the main septic line going to the street, but I don't know what to try next. The bathroom sink and toilet flush no problem in the bathroom right on the other side of the wall. Please help!