Dryer won’t stop running

Your dryer should end the cycle and power down once clothes reach the target dryness. When the drum continues to turn or heat does not stop, the appliance wastes energy, wears out parts faster, and can overheat. In this expert guide you will learn how to recognize the problem, what usually causes it, how to diagnose it safely, and when it is time to call a technician. The guidance below uses clear language and builds on real service practices for modern gas and electric dryers.

How to recognize the problem

• The timer reaches zero yet the drum keeps tumbling or the heater stays on.
• The display shows a few minutes left and sits there for a long time without progress.
• Clothes feel warm and dry but the dryer continues to run without shutting off.
• You hear the end signal and the drum starts again after a short pause.
• The cabinet feels hotter than usual or there is a hot smell that lingers near the vent.

Main causes and practical prevention

• Timer issue or control board logic fault. A worn mechanical timer can fail to advance to the off position. An electronic control board can hang or loop the program after a power surge or a short on a relay. Prevention is limited here, but using a surge protector and keeping the interior free of lint reduces stress on electronics.
• Moisture sensor contamination or sensor issue. Auto dry depends on metal strips that read humidity in the load. Residue from dryer sheets and fabric softeners insulates the strips and makes the board think the load is still wet. Wipe the sensor bars with a soft cloth and a little rubbing alcohol every few weeks to keep readings accurate.
• Restricted air flow in the exhaust path. A packed lint filter, crushed flex duct, long runs with many elbows, or a clogged exterior hood slow the movement of moist air. Clothes stay humid so the cycle never reaches the dry target. Clean the lint screen before every load, vacuum the cabinet seasonally, and have the vent duct professionally cleaned once a year.
• Thermostat or thermistor reading out of range. A stuck cycling thermostat or a drifted thermistor can hold heat on too long or force repeated heat cycles that extend run time. Good ventilation and clean lint passages help parts operate within normal temperature and extend component life.
• Relay or start switch stuck closed. A motor or heater relay that welds contacts closed can keep the drum or heater energized. Power quality and heat control both matter here. Keep internal lint under control to reduce heat stress on relays.
• Settings and human factors. Wrinkle prevent can tumble at intervals after the cycle. Air fluff moves the drum without heat for extended periods. Mixed heavy fabrics can trick auto dry because towels dry slower than shirts. Match the program to the fabric type and turn off extra tumble if you want a full stop at the end.

Similar problems that can mislead diagnosis

• Mode without a defined shutoff The Air Fluff or a continuous tumble option runs until you press Stop. It looks like a fault but it is normal for that selection.
• Temperature control out of range A thermostat that cycles at the wrong point can restart heat and make the session feel endless even though the timer tries to finish.
• Vent duct restriction Poor air flow stretches dry time and makes it look like the cycle never ends when the real issue is moisture removal.
• Weak belt grip or slipping drum Slow or uneven rotation dries poorly and prevents the moisture sensor from reaching the finish threshold. It can be confused with a timer problem.
• Control board reboot loop The program reaches the end and starts again due to a firmware or relay fault. It appears as if the dryer will not shut down.
• Stuck Start button or motor relay The drum keeps turning after the timer expires because the circuit remains closed. This can mirror a timer failure.
• Overloaded drum or mixed heavy fabrics Large dense loads keep the sensor reading wet for a long time. The dryer seems broken while the true fix is to reduce load size or separate fabrics.
• Wrinkle prevent active Periodic tumbling after the end of cycle is a feature that avoids creases. It is easy to mistake this for a fault when you expect a full stop.

Step by step diagnosis you can do safely

• Unplug the dryer or switch off the breaker. Safety comes first. Wait a few minutes and restore power to clear a simple logic hang on the control board.
• Confirm the settings. Make sure wrinkle prevent is off. Use Timed Dry for a test run. If Timed Dry shuts off on time, but Auto Dry does not, focus on the moisture sensor and air flow.
• Clean the lint filter and check air flow. Remove the screen and wash it with warm water if residue is visible. Inspect the vent hose for kinks and feel for strong air movement outside while the unit runs. Weak flow points to a vent restriction.
• Clean the moisture sensor bars. Locate the two small metal strips inside the drum near the lint screen or on the drum baffle. Wipe them with alcohol and a soft cloth. Run a small mixed load and see if the cycle now finishes.
• Listen for the motor turning after time expires. If the drum keeps running with the timer at zero, suspect a stuck relay, a stuck Start switch, or a timer that does not open. If the heater stays on when it should not, stop use and plan for service.
• Observe temperature behavior. If heat cycles very frequently or stays on much longer than usual, a thermostat or thermistor may be out of range. These checks need a meter and access to internal parts.
• Advanced checks for trained users only. With power removed, access the timer or control board and inspect for burned traces, swollen capacitors, or heat marks near relays. Test door switch and belt switch for proper open and close with a multimeter. If you are not comfortable with these steps, schedule a technician.

When to call a technician

• There is a hot smell, visible smoke, or the cabinet is very hot to the touch.
• The drum runs even with the timer at zero and settings that should stop it.
• You find scorch marks on the control board area or hear a relay chatter.
• Breakers trip or the dryer restarts the cycle on its own after the end signal.
• You do not have tools or training to test live circuits and safety sensors.

A professional can trace control voltage from the panel to the timer, verify relay function, read thermistor values, and decide whether the repair needs a new control board or a simple part like a thermostat or timer knob. This saves time and prevents damage to wiring and safety devices.

Conclusion

If your dryer will not stop running, start with settings and air flow because those are the most common and lowest cost fixes. Keep the lint path clear, clean the moisture sensor, and match programs to the fabric load. If the problem continues, the next likely causes are a sensor issue, a timer issue, a panel issue, or a fault on the control board. Timely diagnosis protects the machine from heat stress and keeps energy use in check. When you see signs of overheating or control faults, pause use and bring in a qualified technician.