Like most dryers yours probably has some safety thermostats designed to prevent fires if the exhaust is obstructed or clogged with lint. There should be several high temperature cutout switches mounted on the exhaust piping. Check that none of them are open. There also may be a motor safety switch that only closes when the motor is running at speed. This will be a part of the start/run switch on the motor. IF it is not these two things, you could have a bad gas valve coil.
You will probably find a wiring diagram pasted on the inside of a removable cover that should help you identify the circuit of the ignition sequence in detail.
Orange Hat, December 2006
