Opening the washer to find a drum full of water is never fun. Most drain problems have one of a few causes.
Clogged drain filter
Most front-load washers have a small access panel at the bottom front with a drain filter behind it. Coins, hair ties and lint collect there. Put down towels before opening it.
Kinked or blocked drain hose
Check the hose behind the washer for kinks, and make sure it is not pushed too far into the standpipe.
Lid switch or door lock
Many washers will not drain or spin if they think the lid or door is open. A failed switch or lock stops the cycle.
Failed drain pump
If you hear humming but no water moves, or nothing at all, the pump may be jammed or burned out. This is a common, affordable repair.
Tip: clean the drain filter every few months to prevent most drain problems.