Dryer overheating — Haarlem, North Holland

A dryer that gets excessively hot — scorching clothes, tripping its thermal fuse, or producing a burning smell — is a fire hazard that needs immediate attention. The most common cause is a clogged or kinked dryer vent line: lint accumulates in the 4-inch exhaust duct (especially at bends and where the hose connects to the wall) and restricts airflow, forcing the dryer's heating element to work harder while depriving the drum of the cool incoming air that normally regulates temperature. Over time the trapped heat can ignite the lint itself — according to the U.S. Fire Administration, dryers cause roughly 2,900 residential fires per year, and failure to clean the vent is the leading factor. Beyond the vent, a failing felt drum seal can let hot air bypass the tumbling clothes and concentrate near the motor or belt; a defective cycling thermostat can fail to cut the heating element on and off at the normal 135–155 °F range; and a shorted or stuck heating element can run continuously. On gas dryers a malfunctioning gas valve coil can stick open, producing excess heat. Diagnosis usually starts with measuring exhaust temperature at the outside vent termination (should be 125–135 °F for a properly flowing line) and checking vent hose length and routing against the manufacturer's spec (most dryers max out at 25–35 feet of rigid duct with deductions for each 90° elbow). An appliance repair technician can test the cycling thermostat, high-limit thermostat, and heating element for continuity with a multimeter, replace the thermal fuse if it has already blown, and verify that the vent run meets code — or coordinate with a dryer vent cleaning specialist if the duct needs professional clearing with a rotary brush system.