When too much heat builds up in your dryer, lint or debris in the dryer vent line can ignite, resulting in a dryer fire. The overheat shutoff is the dryer's last attempt to prevent a fire.
Once the heat reaches a certain level, the thermostat will interrupt the electrical connection so the air will cool down. If the thermostat is malfunctioning, the machine can overheat and trip the thermal fuse. Once this occurs, the dryer will not start.
The appliance's outer housing might feel unusually hot when this happens. Be sure to check the flat surface on top of the equipment. Depending on the cause of the problem, your clothes may or may not seem excessively hot. Many dryers will shut off automatically when they overheat.
As your dryer motor ages, wear and tear can cause it to get hotter during a cycle. Sometimes, all that extra heat can activate the thermal overload switch, which prevents a potential fire hazard and shuts off the machine. The motor may restart a few minutes later, once it's cooled down, but the problem won't disappear.
A defective drive motor may be the culprit.
The motor can overheat from lint buildup, or sometimes small items can get inside and cause a blockage. If the dryer makes sound but won't start, there is probably an issue with the drive motor.
Here are the top reasons why: Air flow problem – Poor air flow is the one predominant reason the dryer's heating will be interrupted, causing the dryer to shut off. For gas dryers, poor air flow can result in the flame not being pulled through the burner housing in an adequate manner.
Your Dryer's Auto-Shutoff Kicks In
Most modern dryers come with an auto-shutoff feature. This safety measure will shut off your dryer mid-cycle if it's trapping excess heat and moisture. Trapped heat could be a sign of a blockage in the vent line.
Air Flow Problem
A reduction of the air flowing through the clothes dryer is the number one cause of a dryer overheating or a dryer not drying properly. If your dryer's internal duct has a blockage, hot air becomes trapped inside the machine.
Usually when the dryer stops in the middle of the cycle, it should be an event meant with suspicion, as ignoring it could be dangerous. The most common culprit is that while drying your clothing, the dryer overheated. It tripped the safety features and the dryer shut off to prevent it from starting a fire.
Fires can occur when lint builds up in the dryer or in the exhaust duct. Lint can block the flow of air, cause excessive heat build-up, and result in a fire in some dryers.
One of the most common culprits of a burning smell in your dryer is excessive lint buildup. Remove any lint from the filter, and look inside the dryer itself. There could be a layer of lint in there, too.
The most common reason for a dryer to start and then stop a few minutes later is an overheating dryer motor. If you don't know when your dryer motor was last replaced or are hearing a loud buzzing noise coming from inside the motor, then this is probably your issue.
Many of the permanent press cycles on today's dryers have a cool-down period of around 10 minutes that uses only room-temperature air to help relax wrinkles in fabrics. A cooler fabric will not wrinkle as badly when folded as a fabric dried at a higher temperature.
Dryers are equipped with a safety device that shuts the appliance down when the temperature surpasses a certain point. If your dryer keeps turning off before the cycle is finished, the temperature inside the dryer is not being regulated properly, meaning it's getting too hot and the safety fuse is being tripped.
The most common cause of a dryer shutting off after a few minutes is a broken or faulty drive belt. The drive belt goes around the dryer drum, idler pulley, and the motor pulley and helps the dryer to rotate when operating. If it is defective, the dryer won't work correctly.
If there is a small fire, put it out using a dry chemical fire extinguisher. You should keep one of these in the washer/dryer room for emergencies. You should also store a fire blanket in the room. Use it to smother fires.
Hi-Limit Thermostat:
The hi-limit thermostat will cycle the dryer's burner or heater off if the ducting has become clogged blocking proper airflow. Symptoms are usually a very short heating cycle with a low drum temperature, or no heat at all.
Never leave a dryer running when you're away from home, and never leave it running while you're sleeping.
How Long Do Dryers Take? Typically, a gas or electric dryer should take about 30 to 45 minutes to dry a full load of clothes. Dense fabrics—like a quilt or a load of thick bath towels—may take up to an hour to dry.
A typical drying cycle takes about 45 minutes, but this time can vary depending on the cycle, heat setting and size of your load. Delicate cycles take roughly 15 minutes, while heavy cycles, like bedding, can take up to three hours to fully dry.
The most common include a clogged dryer vent, tripped circuit breaker or unsteady gas flow if it's a gas dryer. The heating element also could be broken or it could also have a faulty thermal fuse.
Common reasons a dryer won't turn on
Appliance is set to “Controls Locked” Tripped circuit breaker. Start button wasn't held down long enough. Dryer door not fully latched.
It is possible for your dryer to get hot but not dry your clothes if it has a poorly functioning motor. If your motor does not run even though it is receiving power, it may be time to replace it. You will likely need to take apart your dryer, including the front panel, top, rear panel and drum.