Sounds like your not getting hot water. On the warm/cold setting, on wash fill, is the water warm or just cold? Could be a bad water valve, clogged screen or no hot water. Turn the wall valve off and unscrew the hot water hose from the valve. Check the screen inside the valve. Run the hot water hose directly into the tub to check that you have hot water. If you have hot water and the screen is clear, the valve is likely bad. Since you hear the solenoid humming, it getting power. You could check with a meter or just swap the connectors and select cold/cold to see if you get hot water. On the cold setting, only the cold valve is open, for warm, both are open, for hot, only the hot valve is open.

Eric