Sorry it has taken so long to answer. Haven't been on the forum in awhile.
My old Atwood has a slider type temperature control that you set about midway for normal hot water. After lighting
the pilot, you rotate the control knob from pilot to "on", "run", or "operate" (or something similar, I forget which at the moment) and you should hear the main burner start and see a flame stretching out beyond the pilot flame.