Frigidaire Dishwasher Leaving Sandy Residue on Glasses:... | appliancefaults.com

Technical Background:

MCU logic and voltage paths. The dishwasher's Main Control Unit (MCU) governs the wash cycle duration, water intake, detergent dispensing, and drain functions. Voltage pathways controlling the fill valve, wash motor, drain pump, and heating element are crucial. Proper function relies on accurate sensor readings (temperature, water level) and reliable relay switching within the MCU.

Symptoms:

US homeowner observations. The dishwasher leaves small, sand-like particles on the bottom of glasses after the wash cycle. The particles are gritty to the touch and difficult to remove with a simple rinse.

Possible Causes:

Hard water mineral buildup.
Detergent not dissolving properly.
Food particles being recirculated.
A failing chopper blade or food disposal system.
Clogged spray arm nozzles.
Issues with the drain pump or filter.

Solution:

1

Inspect the dishwasher filter: Remove and clean the filter located at the bottom of the dishwasher tub. Rinse thoroughly under hot water.
2

Check the chopper blade: Disassemble the lower spray arm assembly and inspect the chopper blade for damage or obstructions. Replace if necessary.
3

Examine the spray arms: Remove the spray arms and clean the nozzles with a small wire or toothpick to remove any clogs.
4

Test the water hardness: Use a water hardness test kit to determine the mineral content of your water. Install a water softener if needed.
5

Verify water temperature: Confirm the water temperature entering the dishwasher is at least 120°F (49°C). Adjust your water heater if necessary.
6

Run a cleaning cycle: Use a dishwasher cleaner according to the manufacturer's instructions.
7

Inspect the drain pump: Check for obstructions or debris in the drain pump assembly. Use a multimeter to check drain pump winding resistance, typically between 10-20 Ohms. If open or shorted, replace the drain pump.

Safety Warning:

Disconnect power to the dishwasher at the breaker panel before performing any repairs. Lock-out Tag-out (LOTO) procedures should be followed to prevent accidental re-energization. Exercise caution when working with electrical components, as 120V AC is present.

Prevention:

Use rinse aid to improve drying and reduce mineral deposits. Regularly clean the dishwasher filter (monthly). Use a high-quality dishwasher detergent. Periodically run a dishwasher cleaner cycle.

Expert Tip:

Some Frigidaire dishwashers have a service mode. To access, press and hold the 'Start/Cancel' button for 5 seconds, then press the 'High Temp Wash' button three times within 3 seconds. This will initiate a diagnostic cycle that can help identify error codes and component failures.

Frequently Asked Questions

•How do I test the chopper blade for proper operation?

The chopper blade should spin freely. If it's seized or has broken blades, it needs to be replaced. You can also check the resistance of the motor winding driving the chopper, it should typically read around 5-10 ohms.

•What type of dishwasher detergent is recommended for hard water?

Use a detergent specifically formulated for hard water, often labeled as such. These detergents contain extra chelating agents to bind minerals and prevent them from depositing on dishes.

•How often should I clean the dishwasher filter?

The dishwasher filter should be cleaned monthly, or more frequently if you notice a buildup of food particles.

Frigidaire Dishwasher Leaving Sandy Residue on Glasses: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the chopper blade for proper operation?

•What type of dishwasher detergent is recommended for hard water?

•How often should I clean the dishwasher filter?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: