Hello group
We live on the 2nd floor of a 3 floor condo building. The washing machine is drained by the hose being stuck into a pipe that diagonally sticks out of the wall about 4-6 inches above the top of the machine. The problem is that no matter what we try, the water backs up in that pipe and comes pouring out the top when the machine drains. We've tried clamping sections of the hose to try and slow the volume of water draining but we almost need to clamp it off completely otherwise it still overflows. We've tried using lesser and lesser amounts of detergent thinking maybe it's the suds that are building up in the pipes and backing the water up but it makes no difference. We've had several machines in here over the years and the problem happens with each of them. Every couple of months we're able to compress and tape part of the machine drain hose and get it set just right so it drains without overflowing. However it keeps coming back.
Anybody have any ideas that don't involve ripping down walls floors and ceilings or paying a plumber $500 to dig through the system?