The heat is regulated with a Klixon mounted next to the blower housing
near the vent pipe so it can judge the temperature of the air coming
out of the drum.Right next to it is a melting type fuse.
If the dryer
runs and gets too hot the fuse will melt.But the dryer will still
run. So if the fuse is good(continuity) and the dryer control(cycle)
thermostat is also good then you should have power going to the gas
valve assembly when the machine is running unless the timer is in the
no heat or wrinkle free/cool down mode. When the gas valve assembly is energized the flame sensor
mounted outside the burner chamber detects the heat from the
ignitor. When the heat is very intense then the sensor shuts down the
and that frees up the power so that the coils can be fully
energised and open the gas gates. The gas comes out and hits the red
hot igniter and you have ignition. It stays on for maybe 2 or 3 minutes
or until the control thermostat is satisfied and shuts down power to
the gas valve assembly.
If your gas dryer has a good flame sensor and a good igniter AND the dryer will work some and quit, replace these:
Gas operator coils
The coils get hot and quit on these machines when they get a
little age on them. It is aggrevating because it is a hard to diagnose
thing. But well worth the 20 bucks.