Most of dishwashers do not stop for water heating. The cycle time pauses till a water temperature sensing device would not report a proper temperature. This is the way how good dishwashers work. Bottom of the line models do not have such devices and water heats up by preset time.
You don't have to pull the dishwasher out of the cabinet to access the water inlet valve. It is accessible from the front after you remove the bottom panel. Shut off the water supply for the dishwasher and disconnect the water line from the water inlet valve. You'll see the screen inside. I usably prefer to replace the water inlet valve instead of cleaning the screen. This part is not expensive and it makes repair more reliable.