First, determine if your glowbar ignitor is "glowing" at all. If it is not, check for power to the glowbar. If it is, check to see if it glows for awhile then shuts off. Power to glowbar but no glow, replace glowbar. if glow bar glows then shuts off, your coils on the gas valve are bad. If the glow bar glows and does not turn off, you have a bad flame sensor switch. If you have no power to the burner assyembly at all, you have to check for an open upstream. A schematic should be on your dryer or in your manual. Hope this helps. Good luck.
Pete
September 2006