Ever since I moved in, the little cup in my dishwasher that's supposed to spring open halfway through the cycle to release detergent has been broken.
Various things I saw online indicated that all I needed to do was purchase a replacement, but I'd been procrastinating. Then I got a renewal notice from the appliance-insurance company.
I'm not sure how I ended up with appliance insurance; I apparently signed up for it sometime during the house-buying process, though I have no memory of doing so. Anyway, it's time to renew, and my first thought was "Why should I renew? I have no use for this," but my second thought was "I wonder if they handle dishwasher repairs."
So I called 'em, and found out that they do handle dishwashers; also refrigerators (even though I didn't have the fridge when I first signed up for the insurance), ovens, microwaves, etc. Not washers or dryers, though; you have to pay extra for that. But they also claim to handle plumbing and electrical/wiring issues. Someone later pointed out to me that that probably means issues related to appliances—dishwasher-related plumbing issues, but maybe not a stopped-up toilet. Not sure; must ask for more info.
At any rate, I told them about the dishwasher, and a day or two later I got a call from an appliance repair guy. He left a message, and I flaked on returning the call. A few days later, he called again, and we arranged a time for him to come by.
He turned out to be Mike Katz of Cool Kat Appliance Repair. He was friendly and entertaining and knowledgeable; he took off the inside of the front door of the dishwasher, messed around with some stuff, and put it back together, and lo and behold, the broken springy-cup-thing now works!
He then proceeded to tell me that GE dishwashers (like mine) have a design flaw: there's a trap at the bottom, underneath a plastic casing held down by screws, where debris collects. Anything larger than, say, a fingertip (I hope you're taking the fingertips off your plates before washing them) ends up there, instead of being washed out the drain. Furthermore, the trap area is right over where the water sprays out, so the water that's being used to clean your dishes is first going through all the debris left over from previous washings. He showed me the underside of the plastic casing (which only had some mildew-looking dark patches; he said he's seen some cases where it's covered with thick green mold), and then he dug out half a dozen melted bits of plastic bags, and an olive pit, and a plastic bread-bag clip thingy, and some bits of broken glass, and other assorted detritus.
It's possible for dishwasher owners to clean that area out themselves, but it requires a screwdriver and it's hard to reach even after you take the plastic cover off. And apparently GE doesn't tell customers they need to do this regularly.
My dishwasher is probably about 15 years old, but apparently more recent GE models have the same problem.
One other thing he mentioned that I'd never heard before, but that makes sense: he noted that the dishwasher starts out by using whatever water is in the pipes, which may be lukewarm or cold. So if you run the hot water in the sink before running the dishwasher, that increases the percentage of the dishwasher's water that's hot.