I finally got my washing machine installed and turned it on with a load of laundry.
Machine:
110.91511100 - Whirlpool built direct drive style Sears washer, top loader, large, built in 1995.The water came out of the top of the standpipe when the machine was pumping water out the drain hose. The standpipe is 2 inch. I'd run a hose down it for a couple of minutes (flow rate about 5 gallons/minute) to make sure it could handle that. This pipe hadn't seen any flow for over 20 years at least. Satisfied that it could handle 5 gallons/minute, I figured I was OK.
Today I finished setting up what I thought would be an adequate drain for the machine. I attached 2 inch black PVC including a trap and extension, properly gluing it all together. The trap accommodates a hand-tightened nut in the middle. The top of the extension tube is 37.5 inches above the floor, well above the 34 minimum recommended by Sears.
I'd duct-taped the drain hose so it couldn't come out of the extension tube from the force of the water. When it came to the point in the machine's cycle where it did the first basket drain, I was surprised to see the water spurting out the top. At least 5 gallons must have come out on my wood laundry room floor and I felt like an idiot for duct taping the hose into the tube because I had to remove that fast so I could start collecting the water in 5 gallon buckets, which I did have right by.
I turned the machine off and repositioned the trap so it didn't twist 20 degrees or so (the way I had it). I reasoned that maybe this diversion was causing the water to back up. But the first expulsion of rinse water (after repositioning the trap) still backed up out the top of the extension tube.
I didn't know the washing machine would pump out the water that fast. It must have been coming out at a rate something like 20 gallons/minute.
I'm wondering if there's any chance this will work if I remove the trap and just put a tube straight up from the stand pipe. Or is the problem that the stand pipe just can't take that kind of flow? I never smelled anything from that stand pipe (like I say, it wasn't used for over 20 years), and I don't know what it connects to or if it's vented. The stand pipe goes under the floor, has a 90 degree elbow (to go horizontal), then a 10 inch straight and another 90 degree elbow to send it down through the concrete foundation of this laundry room extension to the house. This extension looks like an afterthough, and maybe they skimped on the plumbing, etc. I have no idea when it was done, but the house was built in 1910.
Do I have to have this replumbed before I can install a washing machine? Thanks for any help with this.