A clogged drain.
Locate the drain filter (usually bottom right or behind the front panel). Clean it out. Nine times out of ten, this solves the problem.
A washing machine drain clog isn’t just an inconvenience; it’s a water damage risk and a sign that your machine is literally choking on its own waste. Before you call a plumber for an emergency Sunday visit, let’s diagnose the problem, fix it, and prevent it from happening again. Not all clogs are created equal. Depending on where the water stops moving, the fix changes. Here is where to look:
If water still backs up, the clog is deep in your plumbing. Feed a 25-foot drum auger into the standpipe. Crank slowly until you feel resistance. That’s the sludge plug. Break it, retract, and run a rinse cycle to test. The One Thing You Should Never Do Do not pour liquid drain cleaner (Drano, Liquid-Plumr) into a washing machine drain.
If the filter is clean but the water still drains slowly, pour one gallon of boiling water (carefully!) mixed with one cup of white vinegar directly down the standpipe. Wait 10 minutes. The heat and acid dissolve soap scum.