[stillpoint]

I want to hook up a basement-level washing machine drain directly into the main sewer pipe leading from the house, which is about 7 feet up off the basement floor, but the water pressure coming from the drainpipe coming out of the washing machine can't compete with the force of the water coming from upstairs pouring down through the big sewer pipe drain on its way to the septic tank when someone flushes a toilet or is taking a shower, and sewer water backwashes through the opening where the pipe from the washing machine connects to the big sewer pipe, flooding the basement floor. Is there another way to hook the drain pipe coming from the washing machine, maybe some kind of valve so the water can only go one way?

[speedball1]

I want to hook up a basement-level washing machine drain directly into the main sewer pipe leading from the house, which is about 7 feet up off the basement floor, but the water pressure coming from the drainpipe coming out of the washing machine can't compete with the force of the water coming from upstairs pouring down through the big sewer pipe drain on its way to the septic tank when someone flushes a toilet or is taking a shower, and sewer water backwashes through the opening where the pipe from the washing machine connects to the big sewer pipe, flooding the basement floor. Is there another way to hook the drain pipe coming from the washing machine, maybe some kind of valve so the water can only go one way?

Congratulations! By opening up the sewer so that you could drain your washer you've opened up a direct route to the house interior from the septic tank and in so doing exposed your family to a health hazard that plumbers have worked to prevent ever since indoor plumbing. You have allowed sewer gas to invade your home. Sewer gas is a health hazard and the methane content makes it explosive. First cap off the opening and contain the gas.
Next look into a pump that will lift the washer discharge up to the sewer line and third do not connect anything to the sewer main until you have a trap and vent to connect it to. Or you can find another place to place your washer. Good luck, Tom

[suziecox]

Thanks I wasn't aware of the main gases until you metion it I was trying to hook up washer in basement .Suzie