Why a Whirlpool range hood is diagnosed by symptom
A Whirlpool range hood — under-cabinet WVU and UXT or chimney WVW — is a simple ventilation appliance with a motor, a fan wheel, LED lighting and grease filters, and no fault-code display. Because there is no diagnostic screen, a range hood is read by what it does: weak or no airflow, lights out, noise or a dead unit. The symptom itself is the diagnostic.
Airflow and fan symptoms
No airflow on any speed usually traces to a seized or burned-out blower motor, a run capacitor on single-phase motors, a failed control or a wiring fault; the wheel turning freely by hand with no airflow points at an open motor winding, while a wheel that will not turn points at a seized motor. Weak airflow points at a clogged grease filter, a packed charcoal filter on a ductless model, or a blocked or crushed duct. A fan that only runs on one speed points at a speed control or a tachometer-feedback fault.
Light, noise and power symptoms
Lights out with the fan still working points at the LED light bar or its driver, not the motor. Rattling or vibration usually traces to a loose or grease-laden fan wheel, a loose filter or a mounting that has worked loose. A hood that is completely dead — no fan, no lights — points at the supply, the junction-box wiring or the control board. Clean the grease and charcoal filters and confirm the duct is clear before calling. If the hood still will not ventilate, the lights stay dark, or it stays dead after a reset, an experienced, independent technician should diagnose the motor, capacitor, switch, LED driver or control with the correct genuine OEM part. Browse the symptom guides on the range hood diagnostics page, then book range hood repair.