Range hood not extracting well
A hood that runs but does not clear the air usually has a restriction somewhere between the filter and the outside.
Not urgent Weak extraction is a comfort and grease-buildup issue rather than an emergency, though a hood that has become noisy or smells hot should be switched off until it is looked at.
What this symptom usually means
A hood that runs but does not clear the air usually has a restriction somewhere between the filter and the outside. Grease filters that have not been washed in months choke the intake; Whirlpool's guidance is simply that they should be cleaned often. On a recirculating (ductless) hood, the charcoal filter saturates and needs replacing roughly every six months, and a recirculating hood will never move steam out of the kitchen, only trap grease and some odour. On a ducted hood, the duct can be crushed, undersized, run in ridged flex that Broan says creates turbulence, or blocked at the roof or wall cap; Bosch's advice is to check the ducts for blockage, damage or a disconnected joint.
Two things outside the hood also matter. A tightly sealed newer home may not let enough air in to replace what the hood pushes out, so the fan labours and the damper barely opens; Whirlpool notes some installations require make-up air. And a hood mounted too high above the cooktop, or with cabinets closer than the minimum clearance, simply misses the plume. If all that is in order and airflow is still weak, the fan motor may be slowing, the blower wheel may be caked with grease, or a speed control may have failed.
Checks you can do yourself
- Wash the grease filtersPull the metal mesh or baffle filters and wash them in hot soapy water or the dishwasher if the manual allows. If they are bent or the mesh is clogged beyond cleaning, replace them.
- Charcoal filterIf the hood recirculates, find the charcoal filter behind the grease filters and replace it if it is more than six months old or smells of old grease. Charcoal filters cannot be washed.
- Damper and outside capRun the hood on high and check the outside cap (wall or roof) opens and blows. If it does not move, the duct or cap is blocked; birds and lint are common finds. Do not go on the roof.
- Duct behind the hoodIf you can see the duct above the hood or in the cabinet, look for crushed, ridged or disconnected sections. Note the diameter; a hood specified for a 150 mm (6 in) duct on 100 mm (4 in) dryer duct will never perform.
- Make-up airOpen a nearby window a crack and run the hood again. If extraction improves noticeably, the house is too tight for the fan and needs a make-up-air solution from an HVAC contractor.
- UseStart the hood a few minutes before cooking and leave it running a few minutes after; use the rear burners under the deepest part of the hood.
- ControlsCheck the fan is set to a high speed and that any auto or timer mode has not dropped it to low.
Nothing above involves gas, wiring, refrigerant or removing panels.
What our technician checks
These need panels off, live electrical tests or a licensed trade, so they are left to the technician:
- Removing the blower assembly or motor
- Electrical work on the hood's wiring or switch
- Roof work and duct alteration inside walls or attic
Gas appliances, commercial equipment, and Thermador, Miele, Viking, Wolf and Fisher & Paykel appliances: $129 + tax.
Waived when you proceed with the repair. You get the cause, the price and our repair-or-replace verdict in writing before any work.
Repairs a technician may recommend
After inspection, not from the symptom alone.
Blower wheel cleaning or replacement
When the wheel is caked with grease and out of balance, or a blade is broken.
Fan motor replacement
When the motor is slow, noisy or hot, with clean filters and a clear duct.
Speed control or switch replacement
When only some speeds work or the fan runs at one speed regardless of setting.
Damper replacement
When the backdraft damper at the hood or the cap is stuck, broken or missing.
Duct repair or replacement
When the duct is crushed, disconnected, undersized or run in flex. Ductwork beyond the hood connection is often an HVAC or renovation job, and the finding says which.
Hood replacement or re-mounting advice
When the hood is simply too small, too high or the wrong type for the cooktop; we say so rather than sell a repair.
Brands we see with this problem
Codes, parts and access differ by brand; the brand pages cover where the model label is and what to expect.
Cost, and whether to fix it
What the repair costs depends on the part, the labour and whether a second visit is needed for an ordered part; the written finding gives the total before any work. Our guides on what drives repair costs and repair versus replacement explain how to weigh it.
Who to call
RepairWell diagnoses and repairs this in homes and businesses across Ottawa and Gatineau; the diagnostic ($89 + tax at home, $129 + tax for a business) is waived when you proceed with the repair. If the range hood is still under the manufacturer's warranty, contact the manufacturer first: warranty repairs usually have to go through their authorized network.
When to book
Book when the filters are clean, the outside cap opens, and the hood still does not clear the air; when the fan has become noisy, slow or hot; when only some speeds work; or when the damper appears stuck. Tell us whether the hood is ducted or recirculating, the make and model, and whether it is an over-the-range microwave with a built-in fan, since the latter is serviced as a microwave. The diagnostic is $89 + tax and waived when you proceed with the repair. See range hood repair; if a new hood or duct run is the answer, range, cooktop and wall-oven installation covers what we can and cannot do on the ducting side.
We handle this across Ottawa and Gatineau
Related problems
Range hood not extracting well: questions
My hood is loud but doesn't move much air. Why?
Noise without airflow usually means the fan is pushing against a restriction: clogged filters, a crushed or undersized duct, or a stuck damper. Check the filters and the outside cap first.
Can a recirculating hood be converted to vent outside?
Many can, if a duct route to the outside exists and the hood has a ducted option. The duct run itself is usually a renovation or HVAC job; we can advise on what the hood supports.
What size duct does a range hood need?
Broan's guidance is metal duct only, smooth rather than ridged, and never below the size the hood specifies; a common minimum is 150 mm (6 in) round or its rectangular equivalent, with larger hoods needing more.
Does a hood need make-up air in Ottawa or Gatineau?
Newer, tightly built homes and high-capacity hoods can need it; the symptom is a hood that struggles until a window is opened. Your municipality's building rules set the threshold, and an HVAC contractor designs the solution.
Sources
- Bosch: Ventilation hood not extracting
- Whirlpool Product Help: Vent hood not removing smoke or odor
- Broan-NuTone: What type of duct is best for venting a range hood?
Sources checked 2026-09-24.
Book the diagnostic
Tell us this symptom and your postal code; it helps us bring the right parts.
Pick a preferred day and arrival window online; we confirm by email once a technician is assigned.
- $89 + tax diagnostic$129 + tax for gas or commercial appliances and for Thermador, Miele, Viking, Wolf or Fisher & Paykel; waived when you proceed with the repair
- Written finding on every visitCause, price and our repair-or-replace verdict
- 90-day warrantyOn parts replaced; labour depends on the work done