HELP the washer is in the basement and drains into a stand pipe.. it's the last thing on the line.. for 15 years no problem.. now there are times when water comes up out of the standpipe when the washer drains.. very inconsistent sometimes no water sometimes 1/4 cup sometimes 1/2 gallon.. we have had the main drain cleaned out and still are having a problem.. used a wire fish and garden hose to flush out the roof vent pipes.. all water in the house is running fine.. can flush all 3 toilets without a problem.. the real problem is that if the washer is discharging and sometimes flushes a toilet the water sometimes comes out between the toilet and the floor.. not always.. we have had 4 plumbers shrug their shoulders.. the main drain pipe in the basement doesn't seem to be running slow the guys tapped it with screwdrivers and listened to it?? We need advice

Hey Jimbo,

"the real problem is that if the washer is discharging and sometimes flushes a toilet the water sometimes comes out between the toilet and the floor..not always..we have had 4 plumbers shrug their shoulders..the main drain pipe in the basement doesn't seem to be running slow the guys tapped it with screwdrivers and listened to it??? we need advice"

4 plumbers couldn't tell you that you had a partial blockage? And what's a "wire fish"? You say you "cleared" the main drain, but did you snake out the washer branch?
I really love this one. "the main drain pipe in the basement doesn't seem to be running slow the guys tapped it with screwdrivers and listened to it."
You're never too old to learn. To think! All I ever needed to analyze a drainage system was a screwdriver. All these years I've been going about it the hard way, by snaking and running a camera through the lines when all I needed was to tap the pipe with a screwdriver.
Were all the plumbers that came out from the same company? If so the "Plumbers Komedy Klub" must have sent them out because it sure sounds like the only thing you ended up with was a song and dance along with the same problem. You have a partial blockage in your line that can't handle the discharge the washer pump puts out. This blockage is located downstream from the washer in the main. Get some help out there that knows how to address this. Regards, Tom

I swear this is a true story

wire fish=what I call a thin snake

The plumbers were from 4 different companies

the connection from the washer to the main house drain(inside) is new and clear.

The drain from the house to the street was just done professionally

If we disconnect the washer connection and look into the main drain(inside) line and flush the toilets the water runs through fine and the pipe appears dry after the water has run through

Someone suggested an air lock? Because sometimes the water runs through 3 washer cycles fine and then another day we run 1 small load and get water out of the stand pipe

Also when the plumbers were checking the opening to the main drain(outside) and unscrewed the cover that goes through the basement wall they watched as I flushed and ran water and thought it looked OK and that the water seemed to be flowing through fine and stopped as soon as the water passed( no dripping afterward the could signal water getting hung up on a blockage)

Jim,
Backups are caused by only three things. (1) The pipes are too small to handle the discharge. (not likely) (2)ther's a partial blockage in the main. ( but the drains have been cleared) that leaves (3) and I just got through with this one. The washer pump was so powerful that the bends in the system slowed it down enough for it to back up. When the pump stopped everything went back to normal. This complaint was resolved when Maytag came out to the house and replaced the washer with a different model.
I'm attempting to visualize a blocked vent that would cause a back up that would raise up over a closet bend and spill out over the floor. If this was so you would hear a gurgles from fixtures as the system tried to vent. So what's it going to be? Door# 1,2 or 3? Got to be one or the other. Cheers Tom