Most households should have the dryer vent cleaned every 12 months. Homes with long or roof-vented runs, large laundry volume, or pets should do it every 6 to 12 months. Short, straight, wall-vented runs in small households can stretch to 18 to 24 months. Dry times are the real gauge: when a normal load starts needing a second cycle, the vent is telling you it is due.
Why the run matters more than the calendar
Lint accumulates where air slows: elbows, long horizontal stretches, crushed flexible duct, and roof caps. A laundry room on an outside wall with four feet of duct collects a fraction of what a second-floor, roof-vented run in Tollgate Village or Fields of Canterbury collects. Same dryer, wildly different cleaning needs.
Middle Tennessee humidity adds weight. Damp lint mats into felt instead of blowing clear, and exterior hoods here host birds and wasps every spring. Any honest schedule starts with your vent's architecture, not a generic rule.
The warning signs, in order
First, dry times creep up: the 45-minute load takes an hour. Then the laundry room feels hot and steamy during cycles, because moist air is backing up indoors. The outside flap barely lifts while the dryer runs. The dryer's top gets uncomfortably hot. Finally the dryer starts shutting off mid-cycle or pops a thermal fuse, which is the machine protecting itself, and you, from the blockage.
Treat the first sign as the appointment trigger, not the last. Our dryer vent cleaning service measures airflow before and after, so you can see what the cleaning bought. A dryer working against a clean vent also dries faster and lives longer, which our dryer repair page's fault patterns confirm from the other side.
DIY or a service call?
A short, accessible run is a fair DIY job with a rotary brush kit, done slowly so the brush head never gets left in the duct. Roof terminations, runs over about 15 feet, multiple elbows, or any run you cannot fully see are where homeowner kits lose: incomplete cleaning feels productive and still leaves the elbow mats that matter.
If your vent has never been cleaned and the home is more than a few years old, a first professional cleaning with airflow measurement sets a baseline. After that, the rhythm in the answer above keeps it honest, and a calendar reminder beats a thermal fuse every time.