The blower wheel in the dryer moves air through the drum. The motor that turns the blower wheel also runs the belt for the drum. So if the blower wheel gets blocked, it could stop the drum from turning too. Check the blower wheel and housing for anything blocking it. If you see an obstruction, replace the blower wheel or housing. Replacing the part will help get the drum turning again.
The heating element warms the air before it goes into the dryer drum. Over time, the element can burn out so the dryer won't heat up. Use a multimeter to check if the element has continuity. No continuity means the element is burned out. If there's no continuity, replace the heating element. This should fix it so the element heats the air again and the dryer can heat properly.
If the vent line gets clogged or partly clogged, it blocks airflow through the dryer. This makes drying take way longer and the inside gets hotter. It can also cause a burning smell. To keep your dryer working right, you should clean the vent system at least once a year. Cleaning the vents prevents issues like bad smells from the dryer not venting air properly.
Gas dryers have gas valve solenoids that open to let gas flow to the burner. If they fail, the dryer won't heat up. To check, look at the igniter. If it glows but doesn't light the gas, the solenoid is bad. If one or more solenoids are defective, replace them all together. That way the dryer will heat right. The igniter working but not lighting the gas means the gas valve solenoid isn't opening. Replace all the solenoids so the gas can flow again.
The moisture sensor checks how damp the clothes are. It tells the control board when the clothes are dry. If the sensor is broken, it may wrongly show the clothes are dry. Then the drum would stop turning too soon. But this rarely happens. Before replacing the sensor, check the parts that often break first. If those are all working, the moisture sensor likely needs replacing. Follow instructions to remove and replace it safely. Take care not to damage the wiring. Test that the dryer heats and spins after fixing. The sensor helps the dryer know when to stop.
The dryer has a part called a thermistor. The thermistor checks the temperature of the heating part of the dryer. When the heating part gets hot enough, the thermistor turns the heat off. This helps prevent the dryer from getting too hot. If the thermistor is broken, it might not turn the heat on at all. So the dryer won't heat up like it should. The thermistor is an important safety part. It makes sure the dryer doesn't overheat. If your dryer isn't heating, the thermistor could be faulty. It may need to be replaced.
The thermal fuse is a safety device designed to protect the dryer from overheating. The fuse is located on the blower housing or at the dryer’s heat source such as the heating element on electric dryers or at the burner on gas models. The fuse should be closed for continuity meaning it has a continuous electrical path through it when good. If overheated the fuse will have no continuity meaning the electrical path is broken and the fuse has blown. A multimeter can be used to test it for continuity. Be aware that a blown thermal fuse is an indication of a restricted exhaust vent from the dryer to the outside. Always check the dryer venting when replacing a blown thermal fuse.
Too much lint build-up in a dryer can be a fire risk. The heating element can make the lint catch fire. It's best to clean out the dryer and venting once a year. Doing this helps prevent fires from lint build-up.
A lint filter clogged with lint cuts down on air flow. This can make the dryer overheat until the thermal fuse trips. To dry clothes best, clean the lint filter before each load. Dryer sheets can leave buildup on the filter. If you can't blow air through the filter, wash it with soap and water. Use a brush to clean it. Check the filter housing and grille too. Remove any lint in them. Keeping the lint filter clean allows air to flow. This stops the dryer from overheating. Cleaning it before each load is important.