Why lint is genuinely dangerous
Dryers move a huge volume of air — that's how they carry moisture out of your clothes. When the vent duct restricts, two things happen: heat builds up inside the drum housing, and lint that should have been carried outside settles inside the duct instead, where it's sitting directly in a hot airflow.
Lint is extremely flammable. Combined with a restricted duct and a cycling heating element, you have fuel, heat, and airflow in one place. Fire services across Canada flag dryer ducts every year for exactly this reason.
The signs of a blocked vent
Loads take two or three cycles to dry. The laundry room feels humid while the dryer runs. The outside vent flap barely moves when the machine runs. Clothes come out hotter than usual. The machine shuts off mid-cycle — that's the high-limit safety doing its job.
Any one of these means the vent path deserves an inspection this week, not eventually.
The weekend fix
Unplug the dryer (gas dryers: shut the gas valve too). Pull the machine out and disconnect the duct at both ends — usually a spring clamp at the machine and a hose clamp or screw fitting at the wall.
Vacuum the wall-side duct opening with a crevice tool, then run a dryer-vent cleaning brush through the full duct length. Victoria homes with long duct runs through crawlspaces or attics have more elbows — each elbow is a lint trap. Reassemble with metal tape on joints, never screws (screws catch lint).
Replace any plastic or foil flex duct with rigid or semi-rigid metal duct if you can — plastic ducts are a fire code issue in most jurisdictions, not just a performance one.
Finally, check the exterior hood: the flap must move freely and the hood must not be buried under shrubs or a deck.
What a professional adds
When we repair no-heat or slow-dry complaints, the vent check is part of the job: we measure actual airflow at the hood, not just eyeball it. If a thermal fuse has blown, we find out WHY it blew — a fuse on a choked duct is a warning, not a faulty part.
If your duct run is long, inaccessible, or runs through finished space, a professional cleaning with powered brushes is safer than improvising from both ends.