GE gas dryer does run. But no heat on automatic cycles. Thus timer does not advance. On timed cycle the dryer runs. BUT does not heat until I wiggle/move the timer knob, usually to about the 60 minute mark while dryer is already running. Then I hear a click, then I can see the orange glow/ flame followed by the blue flame. The blue flame stays on for a bit, longer than 10 seconds, then shuts off. Maybe a few minutes? Can't say I measured the time beyond 10 seconds accurately. And heat will USUALLY not come on again until I again wiggle the knob on the timer. So usually heating does not cycle. Sometimes I think it does come on again once in awhile. Timer does advance on timed cycle, just clothes usually wet when the dryer stops, a few times they are dry....
Hubby has cleaned dryer, blown out vent, replaced coils ( no change). Removed, cleaned, tested the 3 thermostats, cycling, high cycling, low cycling. Cleaned with alcohol, test in electric skillet by slowly raising heat and measuring continuity. They seem ok. Continuity changes are reasonable, though we do not have a digital display on our skillet....We can hear the click of the thermostats as they go thru temp changes, both up and down...Removed timer. Some contacts were black. Cleaned, resembled.no change in performance. Is timer bad.? anything else to check?