Why Your Range Hood Isn't Working—And How to Fix It

Range hoods fail silently, and you don't notice until smoke fills your kitchen during dinner. The good news: most problems are simple enough to diagnose and fix yourself in under an hour. A range hood that won't draw air, won't turn on, or runs but barely moves anything is telling you something specific. Learning to read those signals—a weak motor, a blocked vent, a disconnected wire—saves you from calling a service tech and gets your kitchen working again. This guide walks you through the most common failures and the straightforward fixes that actually work.

1. Kill the Power First. Turn off the range hood at the wall switch, then flip the breaker for that circuit at your electrical panel. Once power is confirmed off, locate the filter inside the hood—it's usually a metal mesh or pleated cartridge that sits below or behind the fan housing. Pull it straight down and out. Hold it up to a light. If you can't see light through it, it's clogged with grease and dust. This alone will kill airflow.
2. Replace the Clogged Filter. If the filter is metal mesh, soak it in hot soapy water for 15 minutes, then scrub both sides with a soft brush to remove grease buildup. Rinse thoroughly under running water until water runs clear. Shake out excess water and let it air dry completely before reinstalling. If the filter is a pleated cartridge or paper type, do not wash it—these cannot be cleaned effectively and must be replaced. Install the new filter by sliding it into the guides until it clicks or seats firmly.
3. Trace the Duct Path. Locate where the range hood duct exits your home—this is usually through the exterior wall or roof. Follow the ductwork from the hood to the outside. Look for any obvious damage, crushed sections, or loose connections. Gently push on the duct to feel if it moves freely or if something is stuck inside. Check that the duct is not pinched behind the hood or wedged against cabinetry. If the duct is disconnected from the hood or terminates indoors (into an attic or crawlspace), that's your problem—the hood is venting back into the house instead of outside.
4. Reconnect All Loose Joints. If the duct has pulled away from the hood connection, slide it back onto the collar until it's fully seated. Secure it with three evenly spaced stainless steel hose clamps tightened snugly with a screwdriver—hand-tight is fine; do not overtighten or you'll crush the duct. If the duct has pulled away from the wall or roof termination, reattach it and seal the gap with aluminum foil tape (not cloth duct tape, which deteriorates in heat). Work the tape around the seam completely, pressing it down firmly.
5. Snake Out the Blockage. If the duct feels blocked, disconnect it at the hood or the exterior termination point (whichever is easier). Look inside with a flashlight. If you see lint or grease buildup, use a long stick or a plumbing snake to dislodge it. Push debris toward the nearest open end and pull it out by hand wearing gloves. Do this gently—you're clearing buildup, not scraping the duct walls. For a roof-mounted duct, go up on the roof and check the cap; remove any bird nesting material or debris blocking the opening.
6. Check Power at the Breaker. Restore power to the circuit at the breaker panel. Flip the wall switch for the range hood. Listen for the motor humming. If you hear nothing, the breaker may have tripped or the switch may be bad. Go back to the panel and check if the breaker for the hood circuit is in the middle position (tripped). If it is, flip it fully off, wait 30 seconds, then flip it back on. If it trips again immediately when you turn on the hood, you likely have a short circuit in the hood or the wiring—stop here and call a licensed electrician. If the breaker is fine and the switch doesn't turn the motor on, the switch or wiring is the culprit.
7. Swap Out the Failed Switch. If the motor doesn't run but power is at the panel, the issue is likely the wall switch. Turn off the breaker again. Remove the switch plate by unscrewing the two screws holding it. Unscrew the switch body from the electrical box. You'll see two or three wires attached to the switch terminals. Loosen the terminal screws and disconnect the wires—note their positions or take a photo. Buy an identical replacement switch and connect the wires to the same terminals on the new switch. Tighten the terminal screws firmly, push the switch back into the box, and screw the faceplate back on.
8. Free Up the Damper Flap. The damper is a spring-loaded flap at the exterior duct termination that prevents outside air from flowing back into the hood when it's off. Go outside and locate the flap. Push it open gently with your finger—it should swing freely and snap back closed when you release it. If it's stiff, spray the hinges with penetrating oil and work it back and forth a few times. If the flap is damaged, warped, or won't close, it will allow cold air to leak in and reduce the hood's ability to draw air efficiently. Order a replacement damper cap specific to your duct size.
9. Listen for the Clicking Sign. If the hood still won't run after checking power and the switch, the motor capacitor may have failed. This is a small cylindrical component inside the hood that gives the motor a starting boost. Listen carefully when you turn on the hood: if you hear a rapid clicking sound instead of the motor humming, the capacitor is dead. Capacitors are not user-replaceable due to electrical hazard—this requires a licensed appliance tech. Do not attempt to replace it yourself. Call a service technician.
10. Feel the Air Pull. With the hood running, listen for unusual sounds: a grinding noise suggests bearing wear, a squeal indicates a dry blower wheel, and a rattle means something is loose inside. Step back and feel the air coming out of the hood—it should be strong and steady, not weak or sputtering. If the motor is running but barely moving air after you've cleaned the filter and cleared the ductwork, the blower wheel may be coated with grease and needs cleaning. If the motor sounds wrong or the wheel has visible damage, the hood's internal parts need service from a tech.
11. Know When to Call Help. If you've cleaned the filter, cleared the ductwork, verified electrical power, tested the switch, and the hood still isn't working properly, internal motor or bearing failure is likely. Call a licensed appliance repair technician or your hood's manufacturer for warranty coverage information. Document what you've already checked so you can tell the tech what you've ruled out—this saves time and money on the service call.