A 15-Minute Dryer Vent Self-Check
Run the Dryer on High Heat
Use an empty or light load for a few minutes.
Go Outside to the Hood
You should feel a strong, warm stream of air and see the flap open wide.
Look for Lint and Screens
Lint around the opening means a buildup inside. A mesh screen has to go.
Check Behind the Dryer
Look for a crushed hose, loose clamps or a hose without a UL 2158A label.
Time a Normal Load
If a load that used to take one cycle now takes two, the vent is restricted.
Dryer Vent Requirements Under Virginia Code
| Item | Passes when |
|---|---|
| Termination | Exhausts outdoors, with a backdraft damper |
| Screen | None on the dryer termination |
| Clearance | At least 3 feet from openings into the building |
| Exhaust duct | 4-inch smooth-wall metal |
| Length | Within 35 feet after subtracting fitting allowances, unless the dryer maker's installation instructions allow a longer run |
| Transition duct | UL 2158A-listed, 8 feet or less, not concealed |
| Booster fans | None; listed power ventilators only |
| Through the garage | No. 26-gauge sheet steel or heavier, with no openings into the garage (Section R302.5.2) |
Why That Mesh Screen Has to Go
Screens look like a smart way to keep birds out, and they work well on some other vents. On a dryer they catch lint, clog, and block the exhaust. That's why the code bans screens at dryer terminations. A hood with a working backdraft damper keeps pests out instead; bird nest and lint removal covers what to do if something already moved in.
What a Professional Inspection Adds
When to Stop Checking and Call a Dryer Vent Technician
The self-check above answers one question: is air moving? It cannot tell you what the inside of the duct looks like, and it cannot reach a run that goes up through a wall or out through the roof. These findings are the point where a homeowner check stops being useful.
| What you found | What it usually means | Next step |
|---|---|---|
| Weak or no airflow at the hood | Lint blockage somewhere in the run | Professional cleaning |
| Hood flap stuck shut or screened | Lint has nowhere to exit | Hood replacement |
| Foil or plastic hose behind the dryer | Material the code does not allow | Transition duct replacement |
| Flap barely moves even after brushing the vent | A crushed or disconnected section inside a wall or ceiling | Camera inspection of the hidden run |
| Run exits through the roof | Beyond safe ladder work for most homes | Technician with roof access |
| Clothes still damp after a full cycle | Restricted exhaust, whatever the hood shows | Diagnose the slow dryer |
| Burning smell during a cycle | Lint against a heat source | Stop using the dryer, get it checked |
An inspection on its own is rarely the whole job. In practice a technician inspects, then cleans what they find. Dryer vent cleaning in Fairfax and Loudoun runs $135 to $360, depending on the length of the run and where it terminates. If a company quotes an inspection fee, ask whether it comes off the cleaning price when work follows.
Do Home Inspectors Check Dryer Vents?
Many home inspectors note the visible parts, like the hose behind the dryer and the outdoor hood. A general home inspection doesn't run a camera through the hidden line or clean it. Buying a home? Ask the inspector what the report covers, and schedule a dedicated dryer vent inspection if the vent runs long or exits through the roof.
Selling? A buyer's inspector may flag a vent that your own inspector passed years ago, because reports differ in what they note. Ask which item failed, such as a foil hose, a screened hood or a duct through the garage wall, and get the fix documented in writing with photos so the buyer's agent can close the item.