A washer that will not drain is usually protecting you from a flood: it found water it cannot move, so it stops and keeps the door locked. The most common cause is a clogged drain pump filter, followed by a failed pump, a kinked or clogged drain hose, and, on some drains, a blocked standpipe. Work through them in that order.
Start at the filter, because everyone skips it
Most front-loaders hide a pump filter behind a small door at the bottom front. It catches the coins, hair ties, screws, and lint wads that family laundry generates, and in Thompson's Station homes with pets, it loads fast. There is usually a small drain tube beside it to empty the tub slowly into a shallow pan. Have towels ready; there is more water in there than you expect.
Top-loaders vary: some have self-cleaning filters you cannot access, and their no-drain faults lean toward the pump or a sock escaped between the tubs. Either way, forcing the door is never the move; a locked door with water inside is the machine doing its job.
Testing the pump without guessing
If the filter is clean, listen during a drain command. A hum with no water movement suggests a jammed or failed impeller; silence suggests no power to the pump or a dead pump motor; a healthy buzz with slow drainage sends you to the hose and standpipe. A technician confirms with a meter and by checking the impeller by hand, power off.
The mistake to avoid, and it fills appliance forums, is ordering a pump because 'it must be the pump.' Pumps fail, but so do control outputs and hoses, and the parts are not returnable at most suppliers once installed. Diagnosis first is not a sales line; it is the math.
The hose and standpipe nobody checks
A drain hose pushed too far down a standpipe can siphon or airlock; one that is kinked behind a machine shoved back carelessly will strangle flow to a trickle. In newer Thompson's Station laundry rooms, we also find standpipes that partially clog with lint paste over years, so the machine drains fine into a bucket test but not into its own pipe.
If your washer drains sometimes and not others, that intermittency is information: note what load sizes were running and tell us. Our washing machine repair page covers the full diagnosis, and if the tub is full right now, our emergency page explains how to limit the mess.