Thermistor was the likely suspect. Then the water valve solenoid, then the motherboard. I didn’t bother troubleshooting the water valve solenoid before ordering parts because disassembly of the washer is a bit of a pain and because the new valve assembly is quite inexpensive. I replaced both parts and the washer works as new. The valve assembly bench tested ok and the thermistor was bad. Keeping the old valve assembly just in case it’s needed in the future.