I've been having a problem with my DLG033W dryer, and this is probably the only thread on the internet I could find help on.
--Does not heat at all. No glow from the igniter.
--Don't get any voltage from the top plug on the gas assembly. Replaced main board with a used board I found on eBay, "certified working." Still don't get any voltage from the top plug, but I forgot to unplug the dryer when plugging it back in and it shocked the hell out of me.
--Igniter has continuity.
--Flame sensor has continuity.
When I first installed it, it dried fine for maybe a week, with heat. Now it has no heat. Another thing very much worth mentioning, is most of the time we start it, the dryer will buzz loudly. We have to spin the drum a bit and start it again before it will move.
I don't understand why the motor would have anything to do with heating, but I see John mentioned the centrifugal switch on the motor could be an issue.
Yes---based on your additional posts---it's clear that the gas burner is only functioning initially but not continually (intermittent).
This usually caused by the following (in most likely order):
1) Failing MAIN BOARD (6871EC1016C) The gas valve *relay* fails after one or two burner cycles.
2) Failing GAS VALVE ASSY (5221EL2002A) Valve 1 or Valve 2 fails after one or two burner cycles.
3) FLAME SENSOR (6501EL3001A) Erratic operation.
4) CENTRIFUGAL SWITCH on the MOTOR (4681EL1008A) Erratic operation.