A clogged dryer vent is not a maintenance nuisance. It is a fire risk. Lint is highly flammable, dryers generate serious heat, and restricted airflow raises the internal temperature of the machine. It is also one of the most common causes of residential fires — and apartments have an additional complication: longer, sometimes shared, sometimes inaccessible duct runs.
If you notice any burning smell during a dryer cycle, or the top of the dryer becomes unusually hot, stop the cycle and unplug the machine immediately. Do not run it again until the vent has been checked. Never run a dryer with a damaged or disconnected vent.
On this page
Signs your vent is clogged
| Sign | What it means |
|---|---|
| Clothes take two or more cycles to dry | Restricted airflow — classic clog |
| The dryer or the laundry area feels unusually hot | Heat cannot escape |
| A burning or musty smell during the cycle | Lint heating up — act immediately |
| The outside vent flap does not open when running | Blocked duct or disconnected vent |
| Lint visible around the outside vent | Lint is escaping the duct |
| Clothes feel hotter than usual at the end | Airflow restricted |
1. Clean the lint trap properly
Most people pull the lint screen and remove the visible mat. That is only part of it.
- Remove the screen before every load. Non-negotiable.
- Wash the screen every few weeks with soap and warm water. Fabric softener and dryer sheet residue coats the mesh and blocks airflow even when the screen looks clean.
- Dry it fully before refitting.
- Check the trap housing — the slot the screen fits into accumulates lint below the screen. Vacuum it out with a crevice tool.
- Some models have a secondary filter below the lint screen. Check the manual.
2. Clean behind and under the dryer
- Unplug the dryer before moving it. Gas dryers: do not disconnect the gas line yourself.
- Pull the dryer out and vacuum behind and underneath it. This is where lint collects in surprising volume.
- Disconnect the duct from the back of the dryer and check inside the collar — the first 30 cm is where the worst blockage usually sits.
- Vacuum out the dryer's exhaust port with a crevice tool.
- Check the duct for crushing where it bends behind the machine. A crushed flexible duct is a fire risk and chokes airflow.
- Refit the duct securely with a proper clamp — not tape, which dryers out and falls off.
3. Clean the duct itself
This is where an apartment gets difficult. A detached house usually has a short duct to an outside wall. Apartments often have a long horizontal run to a shared chase, or a duct that disappears into the wall.
| Duct type | DIY approach |
|---|---|
| Short duct to outside wall (under 2 m) | Detach both ends and push a vent brush through |
| Medium duct (2–5 m) | Vent brush kit on a drill; work from both ends if accessible |
| Long or concealed duct | Call a professional — brush kits cannot navigate the bends |
| Rooftop or shared chase | Landlord / building management responsibility |
| Flexible foil duct | Replace rather than clean if it is crushed or torn |
- Brush kits attach to a drill and feed through the duct. They work well on straight runs under five metres.
- Leaf blower method — sealing a blower to the duct and blasting air through is effective but messy and not suited to a shared chase.
- Vacuum with a long hose from the outside end, if you have access to the exterior vent.
- Verify airflow afterwards by running the dryer and checking the outside flap opens fully.
4. What to do about a shared or hidden duct
This is the most common apartment situation and the most important to handle correctly. If the duct runs into a wall, a ceiling void, or a shared riser, it is almost certainly the building's responsibility, not yours.
- Check your lease. Most leases make the building responsible for concealed ducts, and the tenant responsible for the lint trap and immediate area.
- Report it in writing to your landlord or building management — a clogged shared duct is a fire risk for every unit on the riser.
- Do not attempt to dismantle walls or ductwork that is not part of your unit. You will not get it back correctly and you will be liable.
- Keep the immediate duct clean — the first metre behind the dryer and the lint trap — so your contribution to the problem is zero.
- Request a professional clean if the building has never had one. Many landlords will arrange it once the fire risk is raised in writing.
The outside vent flap should snap open with force when the dryer runs, and clothes should dry in one cycle. If the flap barely moves, air is not getting out — and if air is not getting out, heat and lint are accumulating in the duct.
5. Prevention and habits
- Clean the lint screen every load and wash it monthly.
- Clean the trap housing monthly with a crevice tool.
- Pull the dryer out and vacuum behind it every three months.
- Have the duct cleaned annually for a long run, every two years for a short one.
- Never use a plastic or foil flexible duct where the manufacturer spec calls for rigid metal. Rigid duct does not sag, trap lint, or burn.
- Keep the area around the dryer clear of anything that could burn.
- Watch for the warning signs — longer dry times are the earliest indicator.
Clean the lint trap every load, wash the screen monthly, vacuum behind the dryer quarterly, and have the duct professionally cleaned if it is long or concealed. Report a shared or hidden duct in writing to your landlord — that is a fire safety issue for the whole building, not a maintenance favour.
Frequently asked questions
What a professional clean involves
| Step | What they do | Why it matters |
|---|---|---|
| Access both ends | Disconnect at dryer and at the outside vent | Finds the real blockage |
| Rotary brush the duct | A powered brush through the full run | Clears lint the vacuum cannot |
| Vacuum extraction | A high-flow vacuum at the far end | Removes loosened debris |
| Inspect the duct | Look for crushing, tears and foil flex duct | A damaged duct must be replaced |
| Check the vent flap | Confirm it opens fully | Restricted airflow is the fire risk |
| Test airflow | Run the dryer and measure | Proves the job worked |
A professional clean costs roughly the same as a service call and usually takes under an hour for an accessible duct. It is worth doing when the duct is longer than about two metres, when it runs through a wall, or when the building has never had one. For a concealed or shared duct it is not optional — it is the only safe route.
If clothes take two cycles, the vent flap barely moves, or you smell burning, stop using the dryer until the duct is cleared. This is the one appliance fault where the consequence is a fire rather than a repair bill.
