Confirm the Control Panel Settting
You have to manually select which water temperature setting to run your machine for each wash load. Set the washing machine to "hot water" on the control console located on the front or top of the washing machine, depending on whether you have a front-loading or top-loading washer. Select "hot water," and start the wash load.
Inspect Hot Water Settings
Verify that the hot water inlet valve is on and that the hot water hose is attached to the machine. Consult your washing machine manual for help locating both parts. After you've located them, turn the valve until it opens. Inspect the hose for kinks that might block water from flowing through it and entering the machine. Replace the hose with a new one if you discover a defect.
Clogged Inlet Valve Screen
Each water inlet valve has a screen that prevents dirt and debris from entering the washing machine when it fills with water. Over time, the screen can become clogged with mineral deposits and rust. When it becomes blocked, water won't enter the machine at the same rate and can cause the machine to under fill. Certain machines will compensate for the water disparity by filling the machine with cold water, which inevitably lowers the temperature of water in the machine. Review the washing machine manual for guidance on how to remove the hot water inlet valve screen to clean it.
Faulty Hot Water Inlet Valve
If the hot water inlet valve fails, hot water simply won't enter the machine to wash or rinse clothes. The water inlet valve is what opens and closes to allow hot water to fill the wash tub. The machine either over or under fills with water when this component breaks. Consult a washing machine technician if you suspect a defective hot water inlet valve is preventing hot water from entering the washing machine to replace the part.