Hi This control panel switch regulates the temperature of the water in the tub. It also plays a role in controlling the fill cycle. If you suspect this switch is faulty, remove it and take it to a professional service person for testing (the test takes special equipment). Or, hook a test wire across the switch terminals; if water flows, the switch is faulty. If the switch is faulty, replace it with a new one of the same type. Connect the new switch the same way the old one was connected.
If there's a problem with both water temperature and tub filling cycles, both the temperature switch and the timer may be faulty. Test both components and replace them as necessary. Procedures for testing the timer can be found below.