Blown Fuse
Most electric dryers have two breakers, and, if either one of them burns out, the electric circuit is disrupted and the dryer will not get power. The fuse in the breaker can blow out for multiple reasons. A surge from a power outage could overload the dryer or an element coil could overheat and cause the circuit to shut down. Another option is the house circuit. If the dryer is pulling more power than the building can handle, or if the dryer is plugged into the same circuit as another power-drawing device, the home circuit will shut off to avoid a potential fire, and the dryer will not function until power is restored.
Clogged Exhaust System
A dryer requires airflow to function properly, and, if the airflow is disrupted, the dryer will not dry clothes successfully. Lint is the most frequent culprit since clothing creates lint as it dries, and that lint will build up significantly if the lint filters or the exhaust system are not regularly cleaned out. The lint can also ignite if too much heat builds up and create a fire risk, so it is vital to regularly clean lint out of the dryer to keep the machine running properly.
Large Load
If the dryer is stuffed full to where the clothing cannot freely circulate through the dryer drum, the clothes won't dry successfully, but they can also cause irregular heat buildup that could damage clothes, cause smoke in the dryer and potentially start a fire. Use smaller loads so the clothing can freely move through the space without being impeded, which helps the clothing dry more effectively, extends the life of your dryer and is also a good idea for safety.
Broken Belt
The dryer drum turns because of a dryer belt that is wrapped around the drum exterior. The belt will wear out over time and can eventually break, which will prevent the drum from rotating, and the dryer cannot function properly. The idler pulley that helps the belt move also wears out at a similar pace, and you could have both devices break around the same time. For that reason, you should also replace the pulley when you need to replace the belt to keep the dryer running properly for a longer period without needing additional repairs.