Amana Dishwasher Error Code 6-4: Float Switch Overflow... | appliancefaults.com

Technical Background:

The dishwasher's MCU (Main Control Unit) monitors the float switch. When the water level rises too high, the float switch activates, sending a signal (typically a voltage change on a specific pin) to the MCU. The MCU interprets this signal as an overflow condition and triggers error code 6-4, shutting down the dishwasher to prevent flooding.

Symptoms:

The Amana dishwasher displays error code 6-4. The dishwasher may not start or may be filled with excessive water.

Possible Causes:

Float switch stuck in the 'up' (overflow) position
Excessive suds in the dishwasher tub
Fill valve stuck open, overfilling the dishwasher
Drain pump malfunctioning, causing water to back up
Clogged drain line, restricting water flow
Faulty dishwasher control board

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Locate the float switch, typically at the bottom of the dishwasher tub. Remove the lower rack and any spray arms to access it.
3

Inspect the float switch and float for obstructions. Clean any debris. Manually move the float up and down to ensure free movement.
4

Check for excessive suds. If present, run a rinse cycle without detergent. Consider using a low-sudsing dishwasher detergent.
5

Verify the fill valve is closing completely. If water continues to enter after the dishwasher is off, the fill valve may need replacement. Use a multimeter to check for 120V AC at the fill valve when it should be closed; if voltage is present, the control board is likely faulty.
6

Inspect the drain hose for kinks or clogs. Disconnect the hose from the drain pump and check for obstructions.
7

Test the drain pump for continuity using a multimeter. If there is no continuity, the pump is faulty. Use a 1/4-inch nut driver to remove the pump's cover.
8

If all other components check out, the dishwasher control board may be faulty and need to be replaced.

Safety Warning:

Disconnect power to the dishwasher at the breaker panel before performing any troubleshooting. Capacitors in the control board can store high voltage even after the dishwasher is unplugged. Use caution when working with electrical components and follow Lock Out Tag Out (LOTO) procedures.

Prevention:

Periodically clean the dishwasher filter to prevent clogs. Use the correct amount of dishwasher detergent. Avoid using excessive soap or detergent not specifically designed for dishwashers. Annually, inspect the float switch area for any buildup of debris.

Expert Tip:

Many Amana dishwashers have a service mode. Consult the technical service manual for your specific model to enter service mode and run diagnostic tests. Often, you can force the drain pump on and off to test it, or activate the fill valve to confirm proper function.

Frequently Asked Questions

•How do I access the float switch on my Amana dishwasher?

The float switch is typically located at the bottom of the dishwasher tub. You'll need to remove the lower rack and any spray arms to access it. In some models, you may need to remove a lower access panel or shield.

•What should the resistance reading be on a good drain pump?

The resistance reading on a good drain pump varies by model, but it's typically between 20 and 120 ohms. Consult the technical service manual for your specific Amana dishwasher model for the correct resistance range.

•How do I know if my dishwasher control board is faulty?

The control board is usually the last thing to suspect. If you've checked all other components (float switch, fill valve, drain pump, wiring) and they test good, and the error code persists, the control board is likely the issue. Also check for burnt components or signs of water damage on the board.

Amana Dishwasher Error Code 6-4: Float Switch Overflow Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the float switch on my Amana dishwasher?

•What should the resistance reading be on a good drain pump?

•How do I know if my dishwasher control board is faulty?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: