Once a year is the answer that fits most households, and it is the one worth defaulting to if you never think about it again. But a two-person apartment with a short run to an exterior wall and a family of five with an upstairs laundry are not the same problem, and treating them the same means one household is paying too often and the other is running a restricted line for months.
Here is how to work out your own interval.
Start at once a year
An average household running four to six loads a week, with a reasonably short run, is comfortable on an annual clean. That interval is short enough that lint never reaches the point of packing solid, which keeps the job simple and the machine efficient.
Then move it closer for each of these
Several loads a day. Volume is the single biggest factor. A household doing two or three loads daily is putting several times the lint into the same pipe, and six months is the sensible interval.
A long or complicated run. Every elbow slows the air, and lint settles where air slows. A twenty-foot run with four turns collects far faster than an eight-foot straight shot to an exterior wall. Upstairs laundries and roof terminations belong in this category almost by definition.
Heavy fabrics. Towels, bedding, fleece and anything with a nap shed far more than shirts do. A household that does a lot of laundry for a large family is loading the line faster than the load count alone suggests.
Pets. Pet hair loads a vent faster than clothing fibre and it mats rather than flows. If you wash pet bedding, or your family’s clothes carry a lot of hair, shorten the interval.
A vented gas dryer. Not because gas machines produce more lint, but because the consequence of a restriction includes the exhaust path, not just heat. Erring on the frequent side is cheap insurance.
A rental between tenants. If you do not know the history, you do not know the condition. Clean it at changeover.
And you can stretch it a little for these
A short, straight run. Six to eight feet through an exterior wall with one elbow or none is the easiest case there is.
Low volume. A single person doing two loads a week is not filling anything quickly.
A rigid metal line, properly installed. Smooth-wall metal does not trap lint the way flexible foil does. If your run is foil accordion duct, ignore this row and shorten the interval instead. That material is the worst thing you can put behind a dryer, and replacing it is a better investment than cleaning it repeatedly.
The machine will tell you before the calendar does
The calendar is a starting point. The real signal is performance.
When a load that used to finish in one cycle starts needing two, the line has narrowed enough to matter. That is true whether it happened in eight months or twenty. The same goes for a laundry room that has started running hot, or lint appearing around the door seal.
Do the outside check once a season: run the dryer, walk outside, look at the hood. The flap should be fully open with a strong flow of warm air. If it is barely lifting, book the clean regardless of when the last one was.
Why “just clean the lint trap” is not the same thing
The trap catches a large share of lint at the drum. It never catches all of it, and what passes goes down the line and settles where the air slows. Cleaning the trap after every load is genuinely good practice and it slows the rate at which the line loads, but it is not a substitute for clearing the run any more than emptying the lint trap is a substitute for clearing the run itself.
Two jobs, different intervals, different people doing them.
The seasonal wrinkle in New Jersey
Summer humidity makes a marginal line worse. The exhaust air is already carrying a lot of moisture, and when the air it is discharging into is humid too, the moisture in the duct condenses more readily and lint sticks rather than blows through.
If you are on an annual cycle and you have a choice, booking before summer is better than after it.
What we do when we arrive
Pull the machine, check the transition hose, work the line from both ends, open and inspect the exterior hood, confirm the damper opens under airflow, run the dryer, and photograph the lint that came out. About an hour for a typical residential run, longer for a second-floor or roof-terminated line.
That is the service. If you are not sure whether you are due, do the exterior hood check first and let the answer decide.
