Whirlpool Dishwasher: Clean Light Blinking 9 Times -... | appliancefaults.com

Technical Background:

The dishwasher's Main Control Unit (MCU) monitors the water softener system via sensors and solenoids. When the MCU detects a fault, such as a regeneration failure or communication error, it triggers the 9-blink clean light error code. The MCU operates on 120V AC power and controls the various components through low-voltage DC signals. Voltage paths must be checked for continuity.

Symptoms:

The Whirlpool dishwasher's clean light is blinking 9 times repeatedly. The homeowner reports that the dishwasher may not be cleaning dishes effectively, and there might be excessive salt usage if a water softener is installed.

Possible Causes:

Water softener regeneration failure.
Faulty water softener valve or solenoid.
Communication error between the MCU and water softener.
Blocked or restricted water softener drain line.
Defective water softener sensor or wiring.

Solution:

1

Disconnect power to the dishwasher at the breaker panel. Use a multimeter to verify 0V AC at the dishwasher's power cord.
2

Locate the water softener unit (if equipped) inside the dishwasher tub, typically near the salt container.
3

Inspect the water softener valve and solenoid for damage or corrosion. Use a 1/4-inch nut driver to access the valve.
4

Check the wiring harness connecting the water softener to the main control board (MCU). Look for loose connections or damaged wires.
5

Use a multimeter to test the resistance of the water softener solenoid. It should typically read between 500-1500 ohms. Replace if open or shorted.
6

Examine the water softener drain line for any obstructions or kinks. Clear the line with compressed air if necessary. Ensure the drain line is properly connected.
7

Reconnect power to the dishwasher and monitor for the fault code to clear. If the issue persists, the MCU may require replacement or reprogramming.

Safety Warning:

Always disconnect power to the dishwasher before performing any repairs. Use Lock-Out/Tag-Out (LOTO) procedures at the breaker panel to prevent accidental re-energizing. Dishwashers operate on 120V AC, which can cause serious injury or death.

Prevention:

Periodically check the water softener salt level and ensure it is properly filled. Run a dishwasher cleaning cycle with a dishwasher cleaner every 3-6 months to prevent buildup and maintain proper function. Ensure the water softener drain line is free from obstructions.

Expert Tip:

After replacing the water softener or MCU, initiate a forced regeneration cycle through the service diagnostic mode to ensure proper calibration and function. To enter service mode, press and hold the 'High Temp Scrub' and 'Heated Dry' buttons simultaneously for 5 seconds. Refer to the service manual for specific command sequences.

Frequently Asked Questions

•What is the typical resistance reading for a functional water softener solenoid?

A functional water softener solenoid typically has a resistance reading between 500-1500 ohms. An open or shorted solenoid indicates a fault.

•How do I access the water softener unit inside the dishwasher?

The water softener is typically located inside the dishwasher tub, often near the salt container. You may need to remove the lower spray arm and any associated components to gain access. Refer to the service manual for specific disassembly instructions.

•Can a blocked drain line cause this error code, even if the water softener itself is functioning properly?

Yes, a blocked or restricted drain line can prevent the water softener from regenerating properly, leading to the 9-blink error code. Ensure the drain line is clear and properly connected.

Whirlpool Dishwasher: Clean Light Blinking 9 Times - Water Softener Fault Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance reading for a functional water softener solenoid?

•How do I access the water softener unit inside the dishwasher?

•Can a blocked drain line cause this error code, even if the water softener itself is functioning properly?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: