Range Hood: Fan Not Working

A range hood where the lights work but the fan does nothing at all — no hum, no movement, nothing — is different from a hood with merely weak suction, and points toward an electrical fault rather than a blocked filter or duct.

The fan speed switch is the most frequent point of failure, especially on hoods with mechanical slide or rocker switches that see years of repeated use. Contacts inside the switch wear out or corrode, eventually failing to complete the circuit at any speed setting. If the lights still work but no fan speed produces movement, the switch is the prime suspect and is usually inexpensive to replace.

Loose or corroded wiring connections are common in range hoods because of the heat and grease-laden environment they operate in over years. Check the wire nuts and connector blocks at the top of the hood where it wires into the house junction box, and inspect for any wires that have become brittle or discolored from prolonged heat exposure.

The fan motor itself can fail electrically, in which case it will produce no sound and no movement even when the switch and wiring test correctly. A motor that hums but does not turn usually has a mechanically jammed impeller — often from a heavy buildup of hardened grease on the fan blades — rather than an electrical failure, and can sometimes be freed by careful cleaning.

Before assuming a major component has failed, always check the home's circuit breaker and any GFCI outlet the hood may share power with in the kitchen, particularly if the lights are also out. A tripped breaker or GFCI is a simple fix that is easy to overlook when troubleshooting an appliance that seems completely dead.