How to Check if an Extractor Fan Is Working Properly

If your extractor fan is making noise but not pulling air, or if your kitchen still smells like last night’s fried fish, it’s not just in your head - the fan probably isn’t working right. Extractor fans in kitchens and bathrooms are meant to remove moisture, smoke, and odors. When they fail, you get mold, mildew, and stale air. Checking if it’s working isn’t hard, but most people skip the basics and jump straight to replacing it. Here’s how to test it properly - no tools needed, and you can do it in under five minutes.

Listen for the motor

Turn the fan on. If you hear a hum, buzz, or whirring sound, the motor is getting power. That’s good. But if you hear nothing at all - no click, no buzz, no movement - the problem could be the switch, the wiring, or a dead motor. Some fans have a delay when turned on, especially older models. Wait 10 seconds. If it’s still silent, move to the next step.

Feel the airflow

Stand directly under or in front of the fan while it’s running. Hold your hand about 6 inches away. You should feel a steady pull of air. If the air feels weak, uneven, or warm instead of moving, the fan isn’t pulling air properly. You can also hold a piece of tissue paper or a light napkin near the grill. If it sticks to the grille and stays there, the fan is pulling air. If it flutters or falls, airflow is too low.

Check the ducting

A clogged or crushed duct is the #1 reason extractor fans seem broken. Even if the motor spins, blocked ducting stops air from escaping. Go to your attic, crawl space, or outside vent. Look for:

• Flaps that don’t open when the fan runs
• Leaves, nests, or debris blocking the outside outlet
• Crushed or kinked flexible ducts
• Condensation pooling inside the duct

In Hamilton, where winters are harsh, ice buildup in the exhaust pipe is common. If the vent cap is frozen shut, the fan will spin but push air back into your home. Clear the ice or replace the vent hood if it’s old and rusted.

Test the timer or humidity sensor

Many modern extractor fans have timers or humidity sensors. If your fan turns off after 10 minutes, that’s normal. But if it doesn’t turn on at all when the bathroom gets steamy, the sensor might be dirty or faulty. Wipe the sensor with a dry cloth. If it’s a timer model, try turning it on manually. If it works manually but not automatically, the sensor or timer module needs replacing.

Check the belt and blades (if accessible)

Some older or high-end extractor fans use belts to drive the motor. If the belt is loose, cracked, or broken, the fan won’t spin even if the motor runs. Turn off the power, remove the grille, and look at the fan blades. Spin them by hand. They should turn smoothly. If they feel gritty, stuck, or wobble, the bearings are worn out. Grease won’t fix this - you’ll need a new motor or whole unit.

Measure the airflow (optional but accurate)

If you want a real number, you can buy a simple anemometer for under $30. Point it at the fan grille and turn the fan on. A good kitchen extractor fan should move at least 80 cubic feet per minute (CFM). For bathrooms, 50 CFM is the minimum. If your fan reads below 40 CFM, it’s underperforming. Most manufacturers list CFM ratings on the fan’s label. Compare your reading to that number.

Common mistakes people make

People often assume the fan is broken because it’s noisy. Noise doesn’t mean failure. A loud fan can still work fine - it might just need cleaning. Others think if the light works, the fan must work too. Not true. The light and fan often run on separate circuits. Also, don’t trust the “on” indicator light on the switch. That just means power is reaching the switch, not that the fan is running.

When to replace it

If you’ve checked all the above and the fan still doesn’t move air properly, it’s time to replace it. Signs you need a new unit:

• Motor runs but blades don’t spin
• Grill is cracked or warped
• Duct connections are rusted through
• It’s over 10 years old and uses more than 50 watts
• You’ve cleaned it twice and it’s still slow

New extractor fans are more efficient. Modern ones use 15-25 watts, move 100+ CFM, and have quiet motors. Look for ENERGY STAR certified models. They’re cheaper to run and last longer.

Quick checklist for testing

Here’s what to check in order:

1. Is the fan making any sound when turned on?
2. Can you feel airflow with your hand or tissue?
3. Is the outside vent clear and opening properly?
4. Does the fan work manually, even if the sensor doesn’t trigger it?
5. Are the blades spinning freely without grinding?
6. Is the CFM output close to the manufacturer’s rating?

If you answered yes to all six, your fan is working. If you said no to any, fix or replace it. Don’t wait until the walls start peeling or the ceiling stains turn green.

Why this matters

An extractor fan that doesn’t work isn’t just annoying - it’s a health risk. Moisture builds up, leading to mold. Mold spores trigger allergies and asthma. In tight, modern homes, poor ventilation can even cause carbon dioxide levels to rise. A working extractor fan keeps your air clean and your home dry. It’s one of the least expensive fixes with the biggest payoff.