GE UltraFresh Vent System Not Turning Off: Troubleshootin... | appliancefaults.com

Technical Background:

The UltraFresh vent system uses a humidity sensor to detect moisture levels inside the washer drum. When humidity is detected, the MCU activates a relay to power the vent fan. The fan runs until the humidity sensor indicates a low enough level, at which point the MCU deactivates the relay, stopping the fan. Voltage paths are 120V AC to the MCU, then low voltage DC to the humidity sensor, and back to the MCU.

Symptoms:

The GE UltraFresh washer's vent system runs constantly, even after the wash cycle is complete. It may run for hours or even days without stopping, potentially causing unnecessary energy consumption and noise.

Possible Causes:

Faulty vent fan relay on the main control board (MCU).
Defective humidity sensor giving false readings.
Wiring harness issue between the humidity sensor and the MCU.
Stuck vent fan motor.
Software glitch in the MCU programming.
Blocked vent duct causing the system to overcompensate.

Solution:

1

Disconnect power to the washer at the breaker panel.
2

Locate the main control board (MCU), typically behind the control panel. Use a 1/4-inch nut driver to remove the panel.
3

Visually inspect the MCU for burnt components or corrosion, especially around the vent fan relay.
4

Disconnect and inspect the humidity sensor wiring harness. Look for damaged or corroded wires. Use a multimeter to test continuity.
5

Using a multimeter, check the voltage to the vent fan motor when the washer is off. It should read 0V AC. If voltage is present, the relay is likely stuck.
6

If the relay appears faulty, replace the main control board (MCU).
7

After replacing the MCU, run a test cycle to ensure the vent system operates correctly. Reassemble the washer.

Safety Warning:

Always disconnect power to the appliance at the breaker panel before performing any repairs. Lock Out/Tag Out (LOTO) procedures should be followed. The main control board operates with 120V AC, which can cause serious injury or death.

Prevention:

Regularly clean the vent duct to prevent blockages. Avoid overloading the washer, as this can lead to excessive humidity. Periodically check the humidity sensor for any visible damage or debris.

Expert Tip:

Some GE washers have a service mode that allows you to manually activate and deactivate the vent fan. Consult the service manual for the specific key sequence to enter service mode and test the vent fan functionality. Press and hold Start/Pause and Temp buttons for 3 seconds. This allows you to force the vent fan on/off to verify operation.

Frequently Asked Questions

•How do I locate the humidity sensor on my GE UltraFresh washer?

The humidity sensor is typically located inside the washer drum, near the top or rear. It may be mounted on the drum wall or near the vent duct. Refer to the washer's parts diagram for the exact location.

•What is the part number for the replacement MCU for my GE UltraFresh washer?

The part number for the replacement MCU varies depending on the specific model number of your washer. You can find the correct part number by searching for your model number on the GE Appliances website or by contacting a GE authorized parts distributor.

•How do I clear the error codes after replacing the MCU?

Some GE washers require you to clear the error codes after replacing the MCU. This can often be done by entering service mode and using a specific key sequence or diagnostic test to clear the error log. Refer to the service manual for instructions specific to your model.

GE UltraFresh Vent System Not Turning Off: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I locate the humidity sensor on my GE UltraFresh washer?

•What is the part number for the replacement MCU for my GE UltraFresh washer?

•How do I clear the error codes after replacing the MCU?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: