How to Troubleshoot & Replace Whirlpool AP6008294 / WP338906 Flame Sensor

Replaced thermal fuse, tested it, found it worked and replaced moisture sensor and flame sensor since I had it apart. This site is the gold standard for DIY. Easy location and identification of parts, ordering, diagnosis and how to videos make this the premier substitute for the time and hassle of finding a repairman to actually return phone calls, show up, have to order parts, then return, usually at a cost of a few hundred bucks. I performed maintenance, fixed the problem and replaced other maintenance vulnerable parts for less than $100 and learned in the process. A bonus: no teaser to access repair tech or products. Hard to believe there's no charge except for the parts; ideal and efficient. 

Fixed! I received professional help and support from Appliance Parts Pros. Thank you 

The way the appliance parts pros have set up their website it made it easy to narrow down the problem and the solution. They have short videos that clearly explain how to replace the part. The parts that I received matched perfectly with the videos. Since my drier is 30 years old, I replaced all the suspect parts, since they were all old and had 30 years of wear. My dryer is working perfectly now. The only concern/complaint is that the parts should be wrapped more carefully for shipping. The way things are thrown around and mistreated in the shipping process mandates that these delicate parts are better wrapped before they leave the warehouse. One of the electrical parts that I received had the electrical tabs bent. Fortunately, I fixed it. But I should not have had to do that. 

I wasn't sure which part was the problem and didn't want to spend time troubleshooting, so I replaced the thermal fuse, gas valve coils, igniter, and flame sensor. 

I installed a new flame sensor. 

Replaced gas valve coils and flame sensor. I avoided removing the drum because I couldn't see any way in h with my forearms I would be able to rethread the belt around the drive pulley and the tensioning wheel behing the blower assembly. That bothered me because the dryer screeches badly when it starts up and I at least wanted to lubricate the support rollers and belt tension wheel. I saw a video on youtube in which a guy actually cut a small rectangular hole in the lower right corner of the right side panel to gain access. There really ought to be an access panel there. Well, I looked closely at my dryer's right side panel and saw that there was an approx. 4" diam recessed circle in the bottom right corner area. It was a knockout, but I was only able to hammer in the top 2/3. I pushed it in and folded it down which gave me access to get my hand in right next to the belt tensioner. I settled for spraying some WD40 on the tenioner wheel as well as the right drum support roller. The dryer is working great and is much quieter as well. 

I replaced the components involved with gas ignition. 

Replaced the Flame sensor and Igniter and dryer works perfectly again. 

With the back panel of dryer removed, Dryer Thermal Fuse and Dryer Cycling Thermostat were very easy to access. Solved lack of heat problem. Other parts ordered required more disassembly for installation. I’ll keep extra parts ordered on my shelf for this aging dryer! 

I originally diagnosed the problem to be the flame sensor but it turned out to be the gas valve solenoids. I ordered ton solenoids and replaced them. Easy fix, dryer working great. Now I have a spare flame sensor.