Our dishwasher of 3 years has started leaving crud on all of the dishes, not getting them very clean. I took the dishwasher parts on the bottom apart, exposing the chopper section, and cleaned out some minor debris, but that had no effect on the dishes.

Next, I turned on the hi-temp wash in the middle of the cycle and the water was hot, but not so hot I couldn't plunge my hand in and keep it there for 20 seconds without being uncomfortable, hardly something one could do if the water was actually heated to 155 degrees as specified in the manual.

Could the heating coil be going bad? We've been running it on hi-temp wash and hi-temp rinse every day for a couple of years.