I have a Maytag Atlantis washing Machine. Many times one wants to fill the tub with COLD WATER. When I set the push button switches to COLD COLD, the machine now fills with hot water.
Please don't think the hoses are reversed. They are not reversed. The machine has worked for years as now hooked up. It just started to not fill the tub with Cold water when set that way. If I set the machine to fill with HOT water it does indeed fill with HOT Water.
I am no expert but suspect the built in thermistor in the control valve is bad or the temperature control board is bad. I have no idea on how to determine which of these two parts is bad. Then too, maybe a third component is bad.

How do I determine what component has failed?