Samsung dishwasher auto light blinking

Brand: Samsung
Model Number: DW80J3020US
Main Symptom: Stops functioning
What happens & when:

Hey guys, my dishwasher auto light blinks after the wash cycle when reaching the rinse cycle. Each time, I can simply switch it off and switch it on then start a new full cycle without issue.

I’ve read that it’s an issue with the water supply, but I don’t understand how it wouldn’t fail on the initial wash cycle, or why it doesn’t fail at all on the full (wash+rinse) subsequent run.

I tried priming the hot water beforehand and during the cycle to make sure hot water is always available, but it didn’t work.

What should I do?

Based on what you’ve described, I don’t think this is a simple water supply problem.

On this Samsung model, the Auto light flashing after the wash cycle usually indicates the control detected a fault and stopped the cycle. While Samsung often associates the Auto light with a fill issue, the fact that it always completes the initial wash, then stops when transitioning to the rinse cycle, tells us we need to look a little deeper.

Here are the most likely causes, in order of probability:

  1. Water inlet valve beginning to fail

    • The dishwasher fills more than once during a cycle. A weak or partially restricted inlet valve may allow enough water for the initial fill but fail to provide enough water during the rinse fill.

    • Sediment in the valve screen or a weak solenoid can cause this intermittent behavior.

  2. Low household water pressure or restricted supply

    • Verify the shutoff valve under the sink is fully open.

    • Inspect the supply hose for any kinks.

    • If your home has recently had plumbing work or hard water buildup, the inlet screen may be partially clogged.

  3. Drain problem causing the control to misinterpret the water level

    • Make sure the dishwasher is draining completely before the rinse cycle.

    • Check the drain hose for kinks or restrictions and verify the garbage disposal knockout was removed if the disposal is newer.

  4. Water level (case break/pressure) sensing issue

    • A dirty pressure chamber or faulty water level sensor can cause the control to think the tub hasn’t filled correctly even though water is entering.
  5. Main control board

    • Less common, but if the valve and water supply check out, the control board may be failing to energize the inlet valve consistently during the rinse fill.

A few tests I’d recommend

1. Observe what happens when it stops

  • Open the door after it flashes.

  • Is there water standing in the bottom?

  • Is the tub empty?

  • Does it sound like it is trying to fill or trying to drain?

2. Check the water fill

  • Start a normal cycle.

  • After the initial fill, open the door.

  • The water level should be just below the heating element.

3. Listen during the transition to rinse
When the dishwasher finishes washing:

  • Does it drain completely?

  • Does it attempt to refill?

  • Do you hear a humming noise with little or no water entering?

A hum without water entering is a strong indication of a failing inlet valve.

I’d also like to know:

  • Does the Auto light blink by itself, or are any other lights flashing?

  • Approximately how many times does it blink before repeating?

  • Is there water left in the bottom of the tub when the cycle stops?

Those answers will help narrow down whether we’re dealing with a fill problem, a drain issue, or a stored fault code. Based on your description so far, my leading suspect is the water inlet valve, with the water level sensing system as the next most likely possibility.