Product review (5 stars): Fixed No Heat issue on Kenmore/Whirlpool dryer
My gas dryer of almost 10 years (Kenmore HE3) was not getting clothes dry.  After monitoring a cycle for a while, I noticed that it was not calling for heat (outbound vent cool - and heating tube not lighting).  I spent about an hour doing some basic troubleshooting.  I figured that the issue was with a sensor, a relay, and igniter, or fuel delivery. Thanks to the interwebs, I was able to find a diagnostic mode and associated codes. Basically, in this mode I was able to run the dryer and call for heat.  After this mode proved that the components required to create heat appear to work, my suspicion was on a sensor I knew existing on the exit side of the blower motor.  I didn't have a multimeter handy to test, but I trusted my hunch as I felt I had eliminated all other parts at this point.  Once this arrived, I spent 5 minutes putting it in and now the dryer runs perfectly.