How to Troubleshoot & Replace Whirlpool AP3094224 / 279769 Dryer Thermal Cut-Off Kit

Replaced the high-limit switch or whatever it’s called. The price of these parts has gone up ridiculously. Making it hard to repair appliances. 

I checked the voltage across the Thermal Fuse, Hi-Limit Thermostat, and Thermal Cutoff. The thermal fuse and thermal cutoff did not show voltage, but the thermostat did. Since you should replace the cutoff and thermostat at the same time, I just ordered the kit as well as a replacement thermal fuse. I replaced the fuse first to make sure it wasn't the only issue and the heating element still did not turn on. I replaced the other two components in the thermal cutoff kit and everything worked fine. Please note that the cutoff component didn't look anything like the original. I suspect it is aftermarket and uses a different type of fuse that looks different than the OEM part. Either way, the parts worked as advertised. 

Tested all components in the heating circuit and found the Thermal Cut-Off was open. 

REPLACED THE THERMAL CUT-OFF. 

First replaced heating element, no change. Then installed new thermal cutoff kit, that did the trick. 

I found the smaller sensor/switch of this kit was open. I initially ordered a cheaper kit that could be delivered the next day. It only lasted 2 dryer cycles when I had again a no heat condition. The same sensor/switch was open. I ordered a 2nd kit and the sensor again opened after 2 dryer cycles. I ordered the Whirlpool kit from AppliancePartsPros.com and the dryer continues to function normally without an issue. 

Replaced the thermal cutoff. 

Replaced thermal cut off kit. 

Replaced thermal cutoff 

I wasn’t sure exactly which part it was, so I changed the Thermal Fuse, Thermal Cut-off, and the Gas Valve Coil Kit.