How to Troubleshoot & Replace Whirlpool AP6008306 / WP3390291 Hi-Limit Thermostat

My dryer wouldn't heat (even though it would turn on and spin). I took back panel off and saw that the high-limit thermostat was burned out (one of the terminals was burnt off). Two screws to put new thermostat in, dryer works fine now! Quick, easy fix. I spent most of the time cleaning lint out of the blower box while I had the rear panel off. 

Replace old thermostat with new one everything working fine. thank you 

Removed and replaced start switch then motor, no joy. removed the timer for disassembly, found bad contact. soldered contact to the spring tab and assembled and installed the timer. All good now. 

Unplugged electric dryer. Replaced thermistor, thermostat and thermal cutoff. Need to take care - scraped skin off on sharp sheet metal. Took about an hour in total; hard to reach 1/4" sheet metal screws holding in components, but basically very simple. 

Ordered 3 parts and everything works great. 

Symptom was that my Whirlpool dryer would run, but without heat. Dryer duct work was clear, and drum spinning would indicate 220v isn't the problem. Skipped testing the timer, and began to test heat related components with an ohm meter. Heating element, themostats, and fuse were good, but the cut-off was the culprit. Choice - repair a 21 year old dryer with a $25 part, or replace the unit? Went the route to repair the dryer after looking at prices of new units. Replacing the thermal cut-off was a quick fix ... back to doing loads of laundry - is that a good thing? Note: While the heating element tested good with an ohm meter, performed a visual inspection. With the rear panel removed, I also had to remove the top panel. A sheet metal screw holds a clip for the element box at the top. Once the heater box is removed, remove the screw holding the element in the box. Remove the element for a visual inspection. Do not try to remove the element while the box is still attached to the dryer for this model (box is one piece and element is approx. 16" long). 

Replaced the end clip. Reatatched the wire to the element. Dryer works fine. 

Replace heating element. Since this dyer is old I also replaced the Hi-limit thermostat and thermal cut off. 

After watching numerous videos on YouTube and reading comments I decerned that my problem was either one or all of the components I bought from AppliancePartsPros.com. Even though the parts I removed from my dryer tested good, I read a comment on one of the videos that the old part could still be faulty. So, I decided that since the dryer would get warm before shutting off that it had to be one of the three parts I ordered: Hi-Limit Thermostat, Dryer Cycling Thermostat, and Dryer Thermal Fuse. After installing all the new parts my dryer works great, like new even though it is 25 years old. The money I spent on parts was so worth it. Replacing all the possible vulnerable parts, I reasoned, will save me the time and trouble of having to deal with another old part wearing out in the near future. Just replace them all and be done with it. Since the price of the parts are very reasonable it was a no-brainer. Good prices, and fast shipping. Thank you to AppliancePartsPros.com 

I listed the dryer model number and problem on the Appliance Parts Pros website. The problem was identified and after watching the associated video, I ordered the parts needed.