Heatilator cab50 not blowing

I just installed a cab50( what a pain) but i go to fire it up and it lights normally and the flame height seems fine, however the convection fan not blowing. I turn the thermostat down because i dont want it to build up to much heat and fry something and then the convection fan starts blowing when its cooling down. Am i being too quiick to act by turning down the thermostat and not letting it warm up enough?

Thanks for any feedback

i waited longer and it starts right up thanks for the input here come the heat!