If your dryer IS heating, but you are experiencing longer dry times and/or poor drying efficiency, the following link can give you some items to check before you assume there is a malfunction with your dryer:http://www.fixya.com/support/r3578821-dryer_takes_too_long_to_dry
The number one cause of dryer heat related problems is poor exhaust ventilation. If not vented properly, a dryer will not dry efficiently, will take longer than required to dry, and will cause the heating circuits to overheat to the point of failure. The dryer will actually seem hotter as the heating circuits begin to overheat. This is also the source of many fire hazards if not resolved. Read through the link provided and review some of the potential causes.
If your dryer runs, but does NOT heat, the following link explains how to troubleshoot an ELECTRIC dryer with a no heat problem:http://www.fixya.com/support/r3576548-dryer_runs_but_does_not_heat
First, begin by unplugging the dryer and verifying the voltage at the wall receptacle. You should read 220-240VAC across the two Hot terminals (left and right slots). If the voltage is incorrect, check to make sure you don't have a breaker tripped. Some homes use 2 separate 120VAC breakers to provide power to the receptacle vice using one 240VAC breaker.
If the voltage IS correct, leave the dryer unplugged and remove the cover plate on the terminal block in the back of the dryer (this is where the power cord is installed). Plug the dryer back in and take a voltage reading across the two hot (RED and BLACK) wires at the terminal block. You should read 220-240VAC. If the voltage is good, you have an internal heating problem. If the voltage is bad at the terminal block, but good at the receptacle, you have a bad power cord.
NOTE: If the wires at the terminal block are not color coded, the outer two wires (left and right) are the hot leads. The center conductor is neutral or ground.
The reason a dryer will still run if the input voltage is incorrect, is because the drive motor only uses a portion of the 220 service. The motor runs off 110-120VAC, while the heating circuits require 220-240VAC. So, if you are missing 1/2 your input voltage due to a tripped breaker or bad power cord, your dryer may exhibit these symptoms.
If you determine the problem to be internal, the heating circuits will either be located in the rear of the dryer on the right hand, or under the dryer drum on the right hand side. Usually, an easy way to determine is by the location of the lint screen filter. If the filter is on top of the dryer, the heating circuits are in the back of the dryer. If the lint screen is in the door, the heating circuits are located under the dryer drum.
The Heating Element is located inside a heater box. The Thermal Cut-Out (TCO) will be located on the outside of the heater box on the end opposite the heating element terminals. The Hi-Limit Thermostat will be located adjacent to the heating element terminals.
If either the TCO or Hi-Limit Thermostat are determined to be bad, replace BOTH components at the same time. That is why these components are commonly sold as a set. Failure to do so may result in premature failure of any parts you replace.
Replacement parts (if required) can be found at the following websites:
The average cost of these components varies, so shop and compare.
NOTE: In many cases the problem is NOT the heating element. The heating element has protection devices that are designed to regulate the heat temperatures. If the dryer overheats the Thermal Cut-Out (TCO) typically will blow BEFORE the heating element. The replacement kit is much cheaper than purchasing a new heating element that may or may not be the problem. Read through the information I provided and take resistance checks to be sure.
If you have any questions, please post back and let me know. I hope you find this information is helpful.