How do I level the washer during installation?

Place a level on the top edge of the washer, checking both side-to-side and front-to-back. If not level, prop the front with a wood block and adjust the feet as necessary, then repeat for the back. After leveling, use a 17 mm open-end wrench to tighten the nuts on all four feet firmly against the washer cabinet — all four feet must be tightened or the washer may vibrate.