Usually the Fixed Thermostat (also known as the High Limit Thermostat) and Thermal Cut-Out (TCO) are used in conjunction to regulate and protect the heating circuits.
The Cycling Thermostat (also know as the Internal Bias) controls the amount of heat required/desired to dry your clothes.
You need to remove the rear panel of the dryer to access the heating circuits on this model dryer. With the back panel removed, the heating circuits will be on the right hand side and the blower fan assembly is located on the left. The Hi-Limit Thermostat and TCO are located on the outside of the heater box with the Hi-Limit Thermostat mounted next to the heating element terminals and the TCO located at the opposite end of the heater box. The Cycling Thermostat is located on the blower fan housing next the Thermal Fuse. It will be the metallic round component, while the Termal Fuse will be a white plastic component.
For better clarification, you can view an exploded view diagram of your appliance at pcappliancerepair.com. If you type in your model number, all the parts I've mentioned are listed under Section 3 (Bulkhead Parts). The components are listed as follows:
Item 6 - TCO/Hi-Limit Thermostat Kit (both parts should be replaced at the same time).
Item 15 - Hi-Limit Thermostat (sold separately)
Item 23 - Thermal Fuse
Item 24 - Cycling (Internal Bias) Thermostat
If you are experiencing heating problems or longer dry times, please review the following link:
Pay particular attention to the section that discusses dryer ventilation. The majority of dryer heat related problems and failures are attributed to poorly installed, clogged, or kinked dryer ventilation. If you haven't had the ducting checked in a while, now may be a good time to do so.
If you have any questions, or require additional assistance, please let me know. I hope this helps you.