Range Hood Fan Not Working
When a range hood's lights work but the fan refuses to spin — or spins very slowly, or hums without moving — you've confirmed the hood has power. The problem is in the fan system itself: the blower wheel, motor, capacitor, or speed switch. The most common cause is a grease-packed blower wheel that's seized or too heavy to spin, followed by a failed run capacitor (which causes the motor to hum without turning). Both are inexpensive fixes. A burned-out motor is less common but also repairable.
Try the AI Diagnosis ToolAI Repair Tools
Common Symptoms
- Fan doesn't spin on any speed setting, but lights work normally
- Fan motor hums when switched on but the blower doesn't rotate
- Fan spins on one speed but not others
- Fan is much weaker than it used to be — reduced airflow and suction
- Clicking or grinding noise when the fan is switched on
- Fan started working intermittently before stopping completely
Most Likely Causes
- 1
Seized Blower Wheel from Grease Buildup (Most Common)
Over time, grease from cooking coats the blower wheel blades and hub. Once buildup is heavy enough, the wheel becomes too heavy or mechanically bound to spin — the motor hums or tries to start but can't overcome the resistance. This is especially common on hoods that have never had the blower wheel cleaned. A thorough degreasing often restores full function without any parts replacement.
- 2
Failed Motor Run Capacitor
Most range hood fan motors use a run capacitor to generate the starting torque needed to spin the blower. When the capacitor fails (which is common after 5–10 years), the motor receives power and hums but lacks the phase shift needed to start rotating. The hum-but-no-spin symptom is the classic sign of a failed run capacitor. Capacitors are inexpensive ($5–$15) and straightforward to replace.
- 3
Burned-Out Fan Motor
The blower motor windings can fail from age, overheating (running with a clogged grease filter), or moisture intrusion. A burned motor may hum (one winding intact, one failed), produce a burning smell, or produce no sound at all. Test the motor winding resistance with a multimeter — a failed winding reads OL (open circuit) rather than the expected 50–300Ω depending on motor size.
- 4
Broken Speed Switch or Fan Control
The multi-speed switch routes different voltage levels or switching signals to the fan motor. A failed speed switch can disable all speeds (looks like a dead motor) or disable individual speed settings. This is more common on mechanical push-button or rotary switches than on electronic controls. Testing involves bypassing the switch to confirm whether the motor itself is functional.
Not sure if this is the right fix for your exact model?
Upload a photo of your appliance label — Fix-It Fast AI will identify your exact unit and tailor the diagnosis.
Quick DIY Checks
Turn off the circuit breaker and verify power is off with a non-contact voltage tester before removing any panels, accessing the motor, or handling capacitors. Capacitors can hold a charge even after power is disconnected — discharge them by briefly shorting the terminals with an insulated screwdriver before handling.
Use a degreaser appropriate for kitchen use. Commercial degreasers like Purple Power are effective but corrosive — wear gloves and eye protection when cleaning the blower wheel. Avoid getting degreaser on electrical components, wiring insulation, or plastic housings.
- 1Test all fan speed settings before disassembling anything: try Low, Medium, and High (or all numbered settings on your hood). A fan that works on one speed but not another points to a speed switch problem, not a motor failure. A fan that produces no airflow on any setting but you can hear a faint hum indicates a motor or capacitor issue.
- 2Turn off the circuit breaker before proceeding. Remove the grease filters (they slide or clip out from the underside of the hood) and look up into the blower housing. Manually rotate the blower wheel with your finger — it should spin freely with minimal resistance. If it's stiff, gummy, or won't move, grease buildup has seized it and cleaning is the first step.
- 3Clean the blower wheel: with power off and the filters removed, soak a stiff brush in a commercial degreaser (Purple Power, Simple Green Heavy Duty, or similar) and scrub the blower wheel blades, hub, and housing. For heavy buildup, remove the blower assembly from the hood entirely (usually 2–4 screws) and soak it in a bucket of hot water with degreaser for 30 minutes. Rinse and dry thoroughly before reinstalling. Test the fan after cleaning before ordering any parts.
Get the full fix — Pro members get unlimited AI diagnoses
Save your repair history, get step-by-step AI guidance on any range_hood issue, and avoid $150+ service call fees.
Try Pro — $7.99/mo- 4Locate the run capacitor: with the hood panel removed (power OFF, breaker confirmed off), find the cylindrical or oval capacitor connected to the fan motor — usually near the motor housing or mounted to the side panel. It has two or three wire leads. Note the capacitor's rated values printed on its label (microfarads µF and voltage, e.g. '5µF 250V').
- 5Test the capacitor with a multimeter: if your multimeter has a capacitance mode (µF), disconnect the capacitor leads, set the meter to capacitance, and probe both terminals. A reading near the rated µF value (within 10%) means the cap is good. A reading far below the rated value, a reading of zero, or OL means the capacitor has failed. Even without a capacitance meter, a capacitor with a bulged top is visually failed and must be replaced.
- 6Check for motor bearing failure: with power off, spin the blower wheel by hand. Grinding, scraping, or clicking during rotation — even with a clean wheel — indicates failed motor bearings. Bearing failure causes the 'hum but no spin' symptom because internal bearing drag prevents the rotor from turning. A motor with failed bearings must be replaced — bearings are not field-serviceable on small appliance motors.
- 7Test the wiring to the fan motor: with a multimeter set to AC voltage, restore power at the breaker, set the fan switch to HIGH, and carefully measure voltage at the motor's two power leads (not the capacitor leads). You should see approximately 120VAC. No voltage at the motor with voltage present at the switch indicates an open wire in the harness between the switch and motor. Identify and repair the break or replace the harness.
- 8Test the fan speed switch: if the motor receives power and the blower wheel spins freely, but only one or no speeds work, bypass the switch by connecting the motor power leads directly to the line voltage (with proper insulation and while being careful — this is a test step with power on, so use insulated probes and do not touch exposed conductors). If the motor runs when bypassed, the speed switch is the problem.
- 9Motor replacement procedure: if the motor tests open-circuit or has failed bearings, order a replacement motor matching your hood's brand and model. Remove the blower housing, disconnect the motor wiring leads (photograph connections before disconnecting), unscrew the motor mounting bracket, and swap in the new motor. Most range hood motors also require moving the blower wheel from the old motor shaft to the new one — the wheel is secured by a set screw.
Save $150+ on a single service call
Less than a cup of coffee — fix it yourself with expert guidance.
- ✓ Step-by-step repair guides with exact part numbers
- ✓ Expert diagnosis in seconds — 500+ problems covered
- ✓ Full tool list & cost estimate before you spend a dime
$150+ service call vs. $7.99/mo · Cancel anytime
Repair vs Replace
A seized blower wheel cleaned with degreaser costs nothing but time and is the most common cause. A failed run capacitor at $5–$15 is one of the cheapest appliance fixes possible. Even a full motor replacement at $30–$80 is well below the cost of a new hood. Only consider replacement if the motor is unavailable (discontinued hood) or the hood is over 12 years old with multiple issues.
Est. Repair Cost
$0–$80 (cleaning free; capacitor $5–$15; motor $30–$80)
Est. Replacement Cost
$100–$400 for a new range hood
Recommended Tools & Parts
- Buy on Amazon →
Range Hood Blower Motor Universal Replacement
Replacement fan motor for range hoods. Search by your hood brand and model number — many hoods use standard motor configurations. Check shaft diameter and rotation direction before ordering.
$30–$80
- Buy on Amazon →
Motor Run Capacitor 5uF 250V
Start/run capacitor for range hood fan motors. Most range hoods use a 3–5µF 250V capacitor. Match the µF and voltage rating printed on your existing capacitor exactly.
$5–$15
- Buy on Amazon →
Range Hood Grease Filter Replacement (Standard Size)
Aluminum mesh grease filter for range hoods. Replace clogged filters — restricted airflow causes motor overheating. Measure your existing filter before ordering.
$10–$25
- Buy on Amazon →
Heavy-Duty Spray Degreaser
Commercial kitchen degreaser for cleaning grease-seized blower wheels and fan blades. Purple Power, Zep, or Simple Green Heavy Duty are effective options.
$8–$15
Links are Amazon affiliate links (tag: fixitfastai-20). Prices are estimates.
Still stuck? Let AI take a look.
Describe your problem or upload a photo — get a diagnosis in seconds.
Related Repairs
Range Hood Not Working
Range hood completely dead — no fan, no lights, no response to any button? Usually a tripped breaker, blown thermal fuse, or failed control board.
Read guide →Range Hood Light Not Working
Range hood light is out, dim, or flickering? Usually a burned-out bulb — but could be a failed LED driver, bad socket, or control board light circuit.
Read guide →Range Hood Controls Not Working
Range hood buttons or touchpad not responding? The most common causes are child lock activation, moisture damage, a failed touch panel, or a faulty control board — most are DIY-fixable.
Read guide →Range Hood Weak Suction — Restore Full Airflow
Range hood running but barely clearing smoke? Weak suction is almost always caused by clogged grease filters, a blocked duct, or a grease-coated blower wheel — all fixable without professional help.
Read guide →Save $150+ on a single service call
Less than a cup of coffee — fix it yourself with expert guidance.
- ✓ Step-by-step repair guides with exact part numbers
- ✓ Expert diagnosis in seconds — 500+ problems covered
- ✓ Full tool list & cost estimate before you spend a dime
$150+ service call vs. $7.99/mo · Cancel anytime
Still not sure what's wrong?
Get an AI diagnosis in seconds — describe the problem or upload a photo.
Get an AI Diagnosis⚡ Get step-by-step help for YOUR specific appliance
Our AI diagnoses your exact model — not just generic advice. Upload a photo or describe the issue and get a repair plan in seconds.
No account needed for diagnosis. Cancel Pro anytime.
Related Tools
Frequently Asked Questions
- Why does my range hood hum but the fan won't spin?
- A range hood motor that hums without spinning has one of three causes: (1) A failed run capacitor — the capacitor provides the phase shift the motor needs to start rotating; a dead capacitor leaves the motor energized but unable to turn. This is the most common electrical cause and the cheapest fix ($5–$15 for a new capacitor). (2) A seized blower wheel — years of grease accumulation can make the wheel too heavy or sticky to overcome the motor's starting torque. Clean the wheel first before replacing any parts. (3) Failed motor bearings — internal bearing failure prevents the rotor from turning even with full power applied. A motor with failed bearings must be replaced.
- How do I clean a range hood blower wheel?
- Turn off the circuit breaker, remove the grease filters, and access the blower wheel inside the hood housing. For moderate buildup, spray the wheel generously with a commercial degreaser (Purple Power or Zep Heavy Duty), let it soak for 10–15 minutes, and scrub with a stiff-bristle brush. Wipe away loosened grease and repeat if needed. For severe buildup, remove the blower assembly entirely (2–4 screws) and soak it in a bucket of hot water mixed with degreaser for 20–30 minutes, then scrub and rinse. Dry completely before reinstalling — moisture in the motor housing causes rust and premature bearing failure.
- Can I replace just the fan motor on a range hood?
- Yes — replacement motors are available for most range hood brands. Search by your hood's brand and model number (on the rating label inside the hood or filter compartment). When ordering, confirm the shaft diameter, rotation direction (CW or CCW when viewed from the shaft end), mounting configuration, and wiring color code. The blower wheel must be transferred from the old motor shaft to the new one — it's usually secured by a small set screw accessed through the hub. Most motor replacements take 45–90 minutes.
- How much does a range hood motor cost?
- Replacement range hood motors typically cost $30–$80 depending on the brand and model. Budget brands and universal motors run $30–$50. Brand-specific OEM motors for Broan, NuTone, Zephyr, and Elica can run $50–$100. In most cases, a replacement motor costs far less than a new hood — repair is almost always worth it unless the hood is very old or the motor is discontinued. Run capacitors (the most common motor-related failure) cost only $5–$15 and should always be replaced before the motor itself.