Bought unit used but had no manual found one online not sure how far to mount from drywall ceiling any input thanks attached photo of manual clearances
I've been reviewing several of these types of heaters and here is a link to installation manual for a Sterling model I just ordered. All of the manuals I've reviewed for different manufacturers indicate minimum 1" clearance.
I have a 45k btu Hot Dawg and the factory mount looks like it has the heater sitting about 2" from the ceiling. I have not measured it, but it is surly closer than the one pictured above.