Hi folks...
Having a problem with my Maytag MTW5900TW top-load washer. Regardless of where the water temperature selector is set to, the washer will fill (or rinse) with whatever water it chooses. If set on cold, it may fill with hot, warm, or cold water. If set on hot, it may fill with hot, warm, or cold water. On top of that, the rinse cycle is supposed to be always cold, but will often times fill with hot or warm. The fill/rinse water temp simply seems to have a mind of it's own.

(edited) - forgot to add that sometimes the water temp will switch mid-cycle, and this is NOT related to hot/cold proportions to get to a warm temp. Recently, the rinse started cold as it's supposed to, then changed to hot. Jogging the temp selector switch around will sometimes changes things, but most times not.

I replaced the selector switch, but that didn't help. I'm suspecting some type of sensor, obstruction, or pc board problem, but don't want to guess again like I did with the selector switch.

Any help appreciated!

The only circuit board, ATC (automatic temperature control), associated with temperature selection is an integral part of the temperature switch and you have replaced that. The temperature sensor that the board uses is an integral part of the water inlet valve assembly so replacing that may fix the problem. Otherwise, it could be a timer problem. The timer has two sets of contacts that are used to tell the ATC whether the washer is in wash cycle or rinse cycle. The timer does not advance during fill though so I think it unlikely that it has anything to do with the problem.

Eric