High-pitched squealing or whining noise from the fan area during cooking.

Safety first: Unplug and cool the unit before accessing the fan. Do not apply oil to sealed electric motor bearings.

Step-by-step checks:

• Confirm source: Run a short cycle and listen to ensure the squeal coincides with fan operation. Stop and unplug.
• Inspect fan alignment: Access the fan and verify it is centered and not rubbing the shroud. Adjust if necessary.
• Spin test: Rotate the fan by hand. A squeal or rough feel indicates bearing wear.
• Avoid lubrication attempts: Most small fan motors are sealed and not designed for lubrication. Adding oil can attract dust and worsen the problem.
• Replace motor: If bearings are noisy, replace the convection fan motor assembly with a GoWISE-compatible part.

When to stop: Persistent squealing is a sign of impending motor failure. Replace the motor rather than continuing to operate it.