Lint buildup, either in the filter or somewhere along the exhaust vent, is the single most common reason a dryer starts taking noticeably longer to dry a normal-sized load. After airflow, an overloaded drum, a washer not spinning out enough water beforehand, and (on electric dryers) an underpowered circuit are the next most common causes.
Clean the lint filter before every load
This is the fastest thing to check and the most common cause by far. A lint screen that looks only lightly coated can still be restricting airflow enough to meaningfully extend drying time — clean it fully before every single load, not just when it looks obviously full.
Check the full exhaust vent run
- Check behind the dryer first
The section of hose closest to the machine is the most common place for a kink to form, especially if the dryer has been pushed back against the wall recently.
- Follow the vent’s full length
Look for crushing, sharp bends, or a run with more turns than the vent is rated to handle — each additional bend adds resistance.
- Check the exterior vent hood
Confirm the flap opens freely during operation and is not blocked by lint, debris, or a bird’s nest.
- Clear lint buildup along the entire path
Lint accumulates gradually inside the hose itself, not just at the filter — a full vent cleaning periodically (not just filter cleaning) is worth scheduling as routine maintenance.
Check the load size
A load too large for the drum restricts the airflow and tumbling action the dryer needs to work efficiently, extending the cycle even with everything else working correctly. If a load looks tightly packed rather than tumbling loosely, split it into two smaller loads.
Check your washer’s spin speed
If a lower spin speed was selected on the washer for a given load, clothes go into the dryer noticeably wetter than they would with a full spin — extending drying time even though nothing about the dryer itself has changed. A higher spin speed or an extended spin option removes meaningfully more water before the load ever reaches the dryer.
Electric dryers on the wrong circuit
Electric dryers are designed to run on a dedicated 240V circuit. If one is mistakenly wired to or run through a standard 120V household circuit, drying time can stretch to roughly three times normal — this is an electrical setup issue rather than anything wrong with the dryer itself, and worth having an electrician confirm if drying time has always been unusually long since installation.
How the moisture sensor affects run time
Modern dryers use a moisture sensor — typically two metal bars inside the drum near the lint trap — to detect when a load is actually dry and end the cycle automatically. If these bars accumulate a film of fabric softener residue, they can stop reading moisture accurately, which can either cut cycles short (clothes coming out damp) or run unnecessarily long. Wiping the sensor bars clean periodically, alongside the lint filter, is worth adding to routine maintenance.
When to suspect the heating element
If lint, venting, load size and spin speed are all confirmed fine but drying time is still excessive, a partially failed heating element (producing some heat, just not enough) is the next likely cause — this is a repair rather than a maintenance fix, and worth having a technician confirm with a multimeter rather than replacing parts by guesswork.
Stop and call a qualified appliance technician or electrician if you find scorched or melted wiring, smell burning, see water that has reached electrical components, or if the fault returns immediately after a repair. Never bypass a safety device — thermal fuses, door interlocks and flood switches fail for a reason, and defeating one converts a broken appliance into a fire or flood risk.
