The causes of heating problems or disabled heating in clothes dryers vary based on dryer type. While electric dryers tend to have one set of issues, gas dryers tend to have another set.
Electric clothes dryers rely on electric coils as their heating elements, which generate heat by stimulating electrical currents. In contrast, gas clothes dryers utilize gas burners as their heating elements, which generate heat by igniting natural gas.
While electric dryers derive their heating power from a home's electrical grid, gas dryers derive their heating power from gas lines. However, both types of dryers utilize electricity for rotating their drums and for powering fans that circulate heat.
Blown Fuse or Circuit Breaker
If the fuse or circuit breaker that supplies power to an electric clothes dryer blows -- or becomes disabled due to a surge in electricity -- the dryer could become entirely disabled. However, with some electric dryer models, separate fuses or circuit breakers supply power to a dryer's heating element and to its motor, which means an electric heating element could lose power from a blown fuse or circuit breaker without the dryer's other functions becoming impaired.
To remedy a fuse or circuit breaker-related dryer heating issue, replace the damaged fuse or circuit breaker with a new one.
Faulty Valve Coil
With gas clothes dryers, a common cause of heating interruptions is a faulty valve coil. A gas dryer's valve coils regulate natural gas as it flows from a gas line to the dryer's heating elements.
If a valve coil breaks, becomes clogged with lint or otherwise malfunctions, a gas dryer's heating element will not receive fuel for combustion and will be unable to generate heat. Remedying a faulty valve coil may require simply cleaning out lint from inside the coil.
Alternatively, you may need to replace the dryer's valve coil.
Faulty Electric Heating Element
Even if fuses or circuit breakers are intact and supplying adequate power, an electric dryer may still have a lack of heat generation. In such instances, a faulty electric heating element may be to blame.
A faulty heating element could be the result of aging or a manufacturing malfunction and typically requires the installation of a replacement. A dryer with a faulty element will likely still be able to tumble clothes and circulate air: just not hot air.