Cleaning a dryer vent means pulling the machine out from the wall, disconnecting the duct behind it, running a flexible brush through the full run to the outside, and vacuuming the loosened lint out of both ends. Most Canadian homeowners can finish the job in under an hour with a dryer vent brush kit, a vacuum and a screwdriver, and the payoff shows up on the next load: a clogged vent roughly doubles drying time, according to insurance brokerage HUB International, which means a fire risk and a higher hydro bill at the same time.
The timing matters heading into fall. From September through April, Canadian households lean on the dryer far harder than they do in summer, because clothes stop going on the line and because coats, towels and bedding all cycle through at the heaviest end of the load range. Lint buildup is the leading cause of more than 15,000 dryer fires in Canada, HUB International reported in October 2023, citing figures from Canadian Residential Inspection Services. Toronto Fire Services puts the same point plainly on its public safety page: a leading cause of dryer fires in homes is simply the lack of dryer maintenance. The full venting system, from inside the dryer to the outdoor vent cap, should be cleaned once a year.
Two parts of this job are not do-it-yourself work, and that is worth settling before the steps begin. First, if your dryer runs on natural gas or propane, do not disconnect, move or reconnect the gas line yourself. In Ontario that work is restricted to a technician certified by the Technical Standards and Safety Authority, and every other province has an equivalent regulator and licensing requirement. Have a certified gas technician pull and reseat the appliance, or clean only the sections you can reach without moving it. Toronto Fire Services also recommends a carbon monoxide alarm in any home with a gas or propane dryer. Second, if your dryer vents through the roof rather than a side wall, do not climb a ladder to reach the cap. Falls from height are among the most serious injuries in home maintenance, and a vent cleaning contractor has the equipment for it. Book one and tell them the termination is on the roof.
For a side-wall vent on an electric dryer, here is the sequence.
- Buy or borrow a dryer vent brush kit. These are sold at every Canadian hardware chain, typically between $20 and $40, and consist of a round brush head on a set of threaded flexible rods that link together to reach four to six metres. You will also want a vacuum with a hose attachment, a flathead screwdriver or nut driver for the duct clamps, work gloves, a flashlight, and a roll of foil tape.
- Confirm your dryer is electric before you move anything. Look behind the machine. An electric dryer has a single heavy cord into a large wall receptacle and nothing else. If you see a flexible metal or black pipe running to a shutoff valve, the dryer is gas, and you should stop and follow the gas guidance above rather than pulling it out.
- Unplug the dryer. Pull the cord from the wall receptacle before you touch the duct. Do not skip this because the job seems quick.
- Ease the dryer away from the wall. Walk it out in small increments, alternating corners, rather than dragging it, and watch the duct behind it so you do not crush or tear the connection. On tile or hardwood, lay a towel or a sheet of cardboard under the feet first.
- Disconnect the duct at the dryer. Loosen the clamp at the back of the machine with your screwdriver and slide the duct off the exhaust collar. If the previous installer used sheet metal screws, note it, because you are going to replace them at the end.
- Clean the flexible section first. Take the loose length of duct outside or into a garage, run the brush through it end to end, and shake the lint out. If the duct is plastic or foil accordion style, replace it rather than cleaning it. Toronto Fire Services warns that plastic and metal foil ducts kink, sag and crush, which traps lint, and that plastic is also more prone to ignition and melting. Use rigid or flexible metal instead.
- Brush out the duct inside the wall. Feed the brush head into the wall duct, adding a rod at a time, and turn it in the direction the rods thread together so they do not unscrew inside the wall. Work back and forth in short strokes rather than forcing the head through in one push. Withdraw it slowly, then vacuum the pile of lint that comes out with it.
- Vacuum the lint trap housing and the back of the dryer. Pull the lint screen out and run the vacuum hose down into the empty chute. HUB International recommends doing this at least once a season, separately from the annual vent cleaning. Vacuum the exhaust collar on the back of the dryer and the floor underneath the machine while it is still pulled out.
- Clear the outdoor vent hood, if you can reach it from the ground. Open the flap, pull out any matted lint, and clear away snow, leaves and any shrub growth crowding the opening. If the hood is above head height or on the roof, leave it to a contractor.
- Reconnect the duct properly. Push it fully onto the collar at both ends and secure it with metal clamps or foil tape. Do not use sheet metal screws: the exposed points inside the duct catch lint and build the exact clog you just removed. Keep the run as short and as straight as the space allows, since every bend is a place lint collects.
- Run the dryer and check the airflow outside. Put it on a timed cycle, go outside, and confirm the vent flap opens and you can feel steady warm air coming out. A flap that stays shut while the dryer runs means airflow is still restricted, and the vent needs more attention before you use the machine again.
- Write the date somewhere you will see it. A note inside the laundry cupboard door, or a recurring reminder on your phone, is enough. The lint screen gets cleaned after every load, the filter chute every season, and the full vent run once a year.
Between cleanings, the dryer will tell you when something is wrong. HUB International lists four warning signs worth acting on immediately: the outside of the machine or the clothing is hot to the touch at the end of a cycle, a load that used to take about 45 minutes now takes far longer, there is a burning smell, or the outdoor vent flap does not open while the dryer runs. Toronto Fire Services adds several habits that cost nothing: never exhaust a dryer indoors, never run one when you leave the house or go to bed, keep the area around it clear of anything that burns, and do not put anything saturated with oil, wax, gasoline or solvent through the drum, because those substances can ignite during the drying cycle even after washing.
Sources: City of Toronto, “Clothes Dryers Fire Safety,” last updated March 26, 2024; HUB International Canada, “Keep It Clean: Avoid Dryer Fires With Regular Maintenance,” October 16, 2023, citing Canadian Residential Inspection Services; Technical Standards and Safety Authority gas technician certification requirements, Ontario.
