How to Test a Kitchen Extractor Fan: Step-by-Step Guide for Homeowners

If your kitchen extractor fan is louder than usual, doesn’t pull smoke out, or just won’t turn on at all, you’re not alone. Thousands of homeowners in Toronto and beyond face this issue every year-especially during winter when cooking indoors increases and stale air builds up. Before you call a technician or buy a new unit, you can test it yourself in under 30 minutes. No special tools needed. Here’s how.

Step 1: Check the Power Supply

Start simple. If the fan doesn’t turn on, the problem might not be the fan at all-it could be the power. First, make sure the circuit breaker hasn’t tripped. Go to your electrical panel and look for the switch labeled "kitchen" or "hood." Flip it off and back on. If it trips again right away, stop. That’s a wiring issue and needs an electrician.

Next, test the outlet. Plug in a lamp or phone charger. If it doesn’t work, the outlet is dead. If you have a hardwired fan (most are), check the wall switch. Some models have a separate switch next to the stove. Flip it on and off a few times. If it feels loose or clicks oddly, the switch might be faulty.

Step 2: Listen for Sounds

Turn the fan on. Don’t just look-listen. A healthy extractor fan makes a steady, low hum. If you hear buzzing, clicking, or grinding, something’s wrong inside. A buzzing sound often means the motor is struggling-maybe the capacitor is failing. A clicking noise could be the relay switch not engaging properly. Grinding? That’s usually worn bearings or debris caught in the blades.

If you hear nothing at all, and you’ve confirmed power, the motor might be dead. But don’t jump to conclusions yet. Clean the fan first. Grease buildup can lock the motor in place.

Step 3: Remove and Clean the Filters

Most kitchen extractor fans have two types of filters: grease filters (metal mesh) and charcoal filters (for recirculating models). Grease filters trap cooking oil. Over time, they get clogged. A clogged filter forces the motor to work harder-and sometimes it won’t start at all.

Take out the filters. Look at them. If they’re thick with grease, dark brown or black, and you can’t see the metal mesh through them, they’re clogged. Wash metal filters in hot, soapy water. Let them dry completely before putting them back. Charcoal filters can’t be cleaned-they need replacing every 3 to 6 months, depending on how often you cook.

After cleaning or replacing filters, turn the fan on again. If it runs smoother and louder, you found your problem. If not, keep going.

Step 4: Test Airflow

This is the most important test. You need to know if air is actually moving.

Grab a piece of tissue paper or a thin plastic bag. Hold it near the fan’s intake (the opening where air gets sucked in). Turn the fan on high. If the paper pulls tightly against the grille, airflow is strong. If it barely moves or flutters weakly, airflow is poor.

Now check the exhaust vent outside. Go to your roof or exterior wall where the duct exits. Turn the fan on. Hold your hand near the vent opening. You should feel strong, steady air pushing out. If you feel nothing, or just a faint breeze, the duct is blocked.

Common duct blockages: bird nests, accumulated grease, collapsed flexible ducting, or a damper stuck shut. If you have a roof vent, a squirrel or raccoon might have moved in. Look for droppings or feathers.

Step 5: Check the Ductwork

Flexible aluminum ducts are cheap and common, but they’re also trouble-prone. If they’re kinked, crushed, or sagging, airflow drops by up to 70%. Rigid metal ducts are better but can still get clogged.

If you can access the duct behind the fan (often in the cabinet above), disconnect it carefully. Use a flashlight. Look for grease buildup. Use a vacuum with a hose attachment to suck out debris. Don’t use water-it can rust metal or ruin insulation.

If your duct runs through the attic or crawlspace, check for insulation wrapped too tightly around it. That can trap moisture and cause mold. Also, make sure the duct isn’t connected to the same vent as your dryer. That’s a fire hazard and violates building codes in Ontario.

Step 6: Test the Motor

If the fan spins slowly or won’t spin at all after cleaning filters and ducts, the motor might be the issue. You can test it with a multimeter if you have one. Set it to ohms (Ω). Disconnect the power. Remove the motor wires. Touch the multimeter probes to the two terminals. If the reading is zero or very low (under 10 ohms), the motor is good. If it shows "OL" (open loop) or a very high number, the motor is dead.

If you don’t have a multimeter, here’s a trick: Gently spin the fan blades by hand. They should turn smoothly with little resistance. If they feel stiff, gritty, or won’t move, the motor bearings are seized. That usually means the motor needs replacing.

Step 7: Consider the Fan Type

Not all extractor fans are the same. There are two main types: exhaust and recirculating.

Exhaust fans pull air out through a duct to the outside. These are more effective and required by code in new builds in Ontario.

Recirculating fans filter air and blow it back into the kitchen. They use charcoal filters to remove odors and grease. These are common in apartments where ducting isn’t possible. But they’re less effective at removing steam and smoke.

If you have a recirculating model and it’s not working well, the problem is almost always the charcoal filter. Replace it. If that doesn’t help, the fan was never designed to handle your cooking habits. You might need to upgrade to an exhaust model.

When to Call a Professional

You can fix most extractor fan issues yourself. But call a technician if:

• You smell burning plastic or see smoke coming from the unit
• The circuit breaker trips every time you turn the fan on
• You can’t access the ductwork or motor without removing cabinetry
• The fan is over 10 years old and parts are discontinued
• You’re uncomfortable working with electricity

A qualified appliance repair technician will test voltage, check the capacitor, inspect the motor windings, and verify duct integrity. Most repairs cost between $150 and $300 CAD. Replacing the whole unit can run $400 to $800, depending on size and features.

Prevent Future Problems

Once your fan is working right, keep it that way:

• Clean grease filters monthly if you cook daily
• Replace charcoal filters every 4 months
• Run the fan for 15 minutes after cooking to clear moisture
• Check the exterior vent twice a year for blockages
• Don’t use the fan as a drying rack for towels or clothes

A well-maintained extractor fan lasts 10 to 15 years. Neglect it, and it’ll fail in 3 to 5. Simple habits save money and keep your kitchen air clean.