Product review (5 stars): This Is an Easy Fix - Replace the Flame Sensor at the Same Time
The Issue: My dryer would heat up, but was taking a long time to dry. Since the dryer heated up, I knew the&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Whirlpool-279311-Igniter-for-Dryer/dp/B004XLDCM0/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Whirlpool 279311 Igniter for Dryer</a>&nbsp;was working. There's two parts that could be suspect, the valve coils and the&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Whirlpool-338906-Sensor-for-Dryer/dp/B004XLDKHM/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Whirlpool 338906 Sensor for Dryer</a>. I ordered both, since once I removed the front of the dryer and the drum, it's really easy to swap out both parts and they are relatively inexpensive. There's several videos on how to remove the front and the drum available on the Internet. I also replaced the&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Exact-Replacement-ER3406107-Dryer-Door-Switch/dp/B00LQDJQGE/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Exact Replacement ER3406107 Dryer Door Switch</a>&nbsp;which was broken, but not needed to fix the lack of heat.

Tools Needed: You'll need a phillips head screwdriver to remove the coils. The sensor requires  a 1/4" nut driver. You might need a 5/16" nut driver to remove the front of the dryer and a flat bladed screwdriver or putty knife.

Results: I plugged in the dryer and it heated up as expected and is working like new.