After reading some of your previous posts about burner you say you have a good flame from burner. Turning the off and on valve should not change flame unless you may have some blockage in the tube to burner as spider web or mud dabber remains.
If you haven't checked before just make sure the tube is clean.
Here is a thread on problems that you maybe having with your fans and you should be hearing the fans cycling off and on during a warm or hot day.
People have had defective heat thermistors that control the fans and the vent space has to be clear to top vent on roof or side wall if on a slide.
Most times even in hot weather the freezer will be plenty cold but box will be warm if both are a problem maybe the fans for 1200 fridge.
If freezer is OK than people have had to add aditional fans in vent area to get box temps down in hot weather.