After pressing the Start button it starts blinking as usual, but there is no sound of heating up. We rinsed the system, but nothing happened.

There should be a way to enter the washing machine into service mode to view an error code. Check your user manual and then you should have your answer!

TRY A RESET CODE
Press the "Sani Rinse," "Heated Dry," "Sani Rinse" and "Heated Dry" buttons on the dishwasher's electronic control panel in quick succession to put the appliance in diagnostic mode.
Close the dishwasher door and engage the door latch.
Wait 10 seconds before pressing the "Cancel" button to reset the dishwasher.

Hi
Open the door. Within 3 seconds press the following sequence --Try pressing normal wash, heated dry, normal wash, heated dry, normal wash, heated dry three times within 6 seconds and then press cancel to reset the dishwasher. If that doesn't help then try pressing Saini Rinse, Heated Dry, Saini Rinse, Heated Dry, Saini Rinse, Heated Dry or Saini Rinse, Air Dry, Saini Rinse, Air Dry, Saini Rinse, Air Dry 3 times in 6 seconds and then the Cancel Button. Close the door and press Cancel.
Blinking lights would stop and should be able to use your dishwasher normally. If the light is still blinking try and reset the power to the dishwasher and try again. If still the light is blinking then check for the connections on the keypad, it may be due to moisture or shorted connections on keypad. Hope this helps... Please post back if you need more information.

Daniel

It sounds like your dishwasher might be locked. You unlock the dishwasher by pressing the "heated dry" button for three secs. and then releasing it, that should do it.

It seems that there is something stucks in your dishwasher...
is there any error code?

I suspect for either of these units that the timer control boards are bad.

I have this same kitchenaid model. It would not start after selecting the wash cycle and pressing start. The light would blink as if the door was open. I did the reset by pushing the sani-rinse, heat dry, sani-rinse, heat-dry and closing the door. You can hear something going on inside. After that stopped (about 3 minutes). I was able to select the wash cycle, press the start, close the door, and it started. Good luck!

I just read this for the same problem: push sanitize, then heat and dry, sanitize, heat and dry, sanitize, heat and dry, cancel, then open and close the door. It worked. The dishwasher is running correctly even as I type this. 

QuietGuard3: Clean light flashing 7 times? Press Heated Dry, press Normal Wash, then press Heated Dry again and press Normal Wash again (that's 4 button-presses) and that should fix it.