Our next theory was that the laundry drain, into which the washer pumps the water through the drain hose, was partially plugged and that water was splashing back out the drain. Lisa also thought that maybe the drain vent had gotten plugged, which would also affect drainage. I called Marraccini Plumbing and made a non-urgent appointment for Steve-the-plumber to come out (next Friday is the first chance) and snake the drain.
This evening, Lisa and I went to Lowe's and bought a large (32 gal/112 l) rubber bucket. We brought it home and rigged it up to test our theories about where the water is going.
We ran the drain hose into the rubber bucket and ran a regular wash cycle: cold water, low water level. The machine filled and began to spin, and we saw no leaks. We advanced it to drain. The water pumped out with no sign of leaks. We then stopped the washer entirely and hauled the water away. (The low-water setting filled the bucket roughly one-third full, and it's much easier if Lisa and I shifted it together.) The water can be dumped into the shower in the main bathroom as long as you don't dump it all at once so the drain has enough time to let the water go down. We took the bucket back and repeated the process for the rinse cycle, with the same results: no obvious leaks.
With the water-only tests done, Lisa ran a load of actual laundry. She had laundry that has needed doing for some days now. Again, this was low water level and cold only. At first everything seemed fine, but partway through the wash cycle, water began to appear around the bottom of the washer. Lisa looked through the holes in the back of the washer and said it looks like water is sloshing out over the top of the drum. There was water splashed all over the inside of the cabinet.
At low level, the amount of leakage is not huge and can be blotted up (so we went ahead and completed this wash-rinse cycle, dumping the drained water from the bucket between cycles). But this is not sustainable. We've bounced between "it's the washer" and "it's the drain" a few times, with stops at "it's this hose or that." But now it does seem that it must be the washer has a small leak of some sort.
None of the machines at Lowe's (including the equivalent low-end to what we currently have) look good to Lisa. She says there are either too many controls or the ones that are on the machines are too flimsy, or both. We will go into Reno/Sparks tomorrow and look at what we can find there. I hope we can find something that works. I don't like fussing with appliances.
Now I will need to call and cancel the plumbing appointment for next Friday, but that will have to wait until Tuesday; it's not urgent.