Gas dryer runs, but no heat.

Unplug the dryer and remove the front panel (two screws at bottom of the panel), being careful of the door switch wires attached to the front panel. Using an ohm meter, I checked the ignitor for continuity and found it was open (should be 50-100 ohms). Make sure to check the solenoids on the gas valve. When the igniter goes bad, it will usually burn out the valve 1 solenoid boost coil (the one with 3 terminals), which was the case with my dryer. The solenoid coils are held in by a bracket with two screws (series 01 dryer) and are easy to remove and replace. Be careful replacing the igniter as the heating element is VERY fragile. Take the time to vacuum out all of the accumulated lint and dust inside the dryer while the front panel is removed, including the lint trap and duct. New igniter and boost/hold solenoid fixed the problem.