I have an Amana gas dryer about 10 years old. The dryer will heat and the timer will advance on the timer cycle but it will not heat on the heat/more heat cycle. I have cleaned the lint vent entirely. I can see the ignitor get red hot and then ignites the gas on the timed setting. I am not sure what to check next. Please advise.

Does the timer advance when in the heat/more heat cycle?

No. The timer on the heat/more heat cycle does not advance. It has ignited but only for a few minutes. Then it shuts off and does not heat any more and does not advance.

The Time cycle is working. I have been watching it. It ignites, stays heated and advances.

I do hear a funny sound though - almost sounds like a toilet running continuously - but then the sound turns off. Is it the gas selenoid valve malfunctioning?

I was going to take the gas valves off and have them checked.

What are your thoughts.