Whirpool Quiet III Clean light blinks

You, my friend, have the dreaded 'blinking clean light.' This means that the electronic control has detected that for three consecutive cycles,
1. the heater hasn't come on
OR
2. the water hasn't come into the dishwasher
OR
2.5. the water came in, but wasn't spraying around inside.
OR
3. the heater came on, but the temperature probe did not detect a 3 F degree rise in temp in a certain alotted time. (Is the water supply unusually cold?)

Originally, this fault code could happen if any of these happened just once. Now they program the elec control to wait until the 3rd consecutive ocurrence.
First, let's clear that fault code.
Since you did not mention any unusual sounds, I will assume the water is filling and spraying around inside.
Press 'heated dry', 'normal', 'heated dry', 'normal'. This activated the test cycle, and clears any fault codes. After 10 seconds, press 'cancel'. Open the door and carefully see if the heating element came on. (It should be hot.)
If it did come on, it's an intermittent problem, and could be related to the door switch. Some earlier models would allow the dishwasher to run with only one of the two contacts closed, but the heater would not come on. Be careful to close the door tight each time. They have redesigned the switch (or is it the door latch?) to ensure both contacts get closed.
If the heater did not come on, then you might need (in order of higest to lowest probability) a heater, a heater thermostat, or the electronic control board (heater relay.)
I haven't ever seen a failed temperature sensor, though it is theoretically possible.
You can continue using your dishwasher until it is repaired. Though, you may have to reset the fault code 2-3 times a week.

Good luck!