For most homes, a dryer vent needs a full cleaning at least once a year, and more often if you run a lot of loads, have a long vent run or do laundry upstairs. The lint screen catches most of the lint, but not all of it. What slips past settles inside the duct a little at a time, until the dryer starts running hot and taking longer to dry.
Below is a practical schedule, the warning signs that your vent is overdue, the codes some dryers display, and why Calgary winters add an extra problem at the outside hood.
The basic rule: at least once a year
An annual full vent cleaning is a good baseline for a typical household. Some homes need it twice a year, and the lint screen itself needs attention every single load.
| Task | How often | Who does it |
|---|---|---|
| Empty the lint screen | Every load | You |
| Wash the lint screen | Every 2 to 3 months | You |
| Check the outside hood | Monthly, weekly in cold snaps | You |
| Clear the transition duct | Every 6 months | You or a technician |
| Full vent run cleaning | Once a year | Technician |
| High-use or long-run homes | Every 6 months | Technician |
When to clean more often
- You have a large family or run the dryer most days.
- You have pets that shed.
- Your vent run is long or has several bends.
- The laundry room is on the second floor or in the middle of the house.
- You dry a lot of towels, bedding or fleece, which shed heavily.
Signs your vent needs cleaning now
Do not wait for the calendar if you notice any of these:
- Loads take longer than they used to, or you are running a second cycle. See our post on a dryer that takes two cycles to dry.
- The top of the dryer or the laundry room feels unusually hot.
- Clothes come out very hot but still damp.
- You notice a burning or hot-lint smell.
- The outside flap barely opens when the dryer is running.
- Lint is gathering around the outside hood or behind the dryer.
Vent codes on newer dryers
Many newer dryers measure airflow and tell you when the vent is restricted. LG Flow Sense shows d75, d80, d90 or d95, where the number is the percentage blocked; our LG Flow Sense post explains each one. Samsung's vent test can show C80 or C90 for a vent that is about 80% or over 90% blocked, or Clg when it is clogged. Whirlpool-built dryers display AF or Check Vent, GE shows CLg, and Electrolux shows EF1 for a blocked vent. Most of these dryers keep running, but they run slower and hotter until the vent is cleared. The full list is on our dryer error codes page.
Why a clean vent matters
A clean vent is about more than shorter drying times. Lint is very flammable, and a dryer pushing hot air into a partly blocked duct runs hotter than it was designed to. That heat stresses the thermal fuse, the high-limit thermostat, the heating element or burner, and the motor. Many of the no-heat and overheating repairs we do start with a restricted vent.
A blocked vent also wastes energy. The dryer runs longer for every load, and on a gas model the burner cycles more often. Clothes take more wear from the extra heat and tumbling. Our post on dryer fire safety and lint covers the fire side in more detail, including why lint builds up inside the cabinet as well as the duct.
Long runs and upstairs laundry
The longer and twistier the duct, the more places lint can settle. Upstairs laundry rooms are common in newer homes, and their vents often run through the attic or between floor joists to reach an outside wall or the roof. Those runs are long, hard to inspect, and sometimes sag in spots where lint and moisture collect.
What a good vent looks like
- Rigid or semi-rigid metal duct with as few bends as possible.
- Foil tape on the joints, not screws, which snag lint inside the duct.
- A short, uncrushed transition duct behind the dryer.
- A hood with a working flap and no screen to catch lint.
White vinyl or foil accordion duct traps lint and should be replaced. Roof vents with screens are a trouble spot, because the screen clogs quickly and is hard to reach.
Calgary winters and frost on the hood
When warm, humid dryer air hits a vent hood at minus 20, the moisture freezes. Frost builds on the flap and around the opening, and lint sticks to the frost. Over a few weeks the hood can close up almost completely. The dryer then runs hot, takes far longer and may trip its thermal fuse or high-limit thermostat. Check the hood regularly during cold snaps, and after heavy snow make sure drifts have not buried it. Our post on winter dryer vents, frost and fire risk goes deeper.
Keeping the hood clear in winter
- Look at the hood from outside every week or two when temperatures drop well below zero.
- Knock frost off the flap gently with a gloved hand or a soft brush. Do not chip at it with a metal tool.
- Keep snow shovelled back from low hoods, and never pile snow against the wall where the vent exits.
- Do not add a screen or cover to stop birds. Screens catch lint and frost and block the hood faster.
A hood that frosts up after every few loads can mean the duct slopes the wrong way and lets condensation run back, or that the run is long enough for the air to cool before it exits. Both are worth having checked.
Safe checks before you call
Unplug the dryer before you move it or touch the duct. Then:
- Clean the lint screen, and wash it with warm, soapy water if it looks glazed.
- Ease the dryer out and check the transition duct for kinks or crushing.
- Disconnect the transition duct, clear any lint you can reach by hand or with a vacuum, then reconnect it securely.
- Plug the dryer back in, run it briefly, and check outside that the flap opens with strong airflow.
- Clear frost, snow or nests from the hood. Do not climb onto a roof to reach a vent.
On a gas dryer, take care not to bend or strain the gas connector when you pull the dryer out, and never disconnect it yourself. If you smell gas, leave the house and call ATCO Gas emergency at 1-800-511-3447.
When to call a technician
If it has been more than a year, your run is long or goes through the attic, or the dryer still runs hot after these checks, it is time for a professional cleaning. We clean the full run from the dryer to the hood with rotary brushes and air, check for crushed, sagging or disconnected sections, clear the hood and flap, and test airflow afterward. If we find vinyl or foil duct, or a run that is too long for the dryer, we will explain the options. If the dryer has already stopped heating because a fuse or thermostat tripped, our dryer not heating service covers that repair too.
Book a dryer vent cleaning or call Fast Appliance Repair at (587) 779-6919. We serve Calgary, Airdrie, Crossfield and nearby towns with same-day appointments, a flat diagnostic fee, a full quote before any work and a 90-day parts and labour warranty on repairs.