RETURN AIR FLOW...........if restricted furnace will shut down, not run, keep tripping, overheat the heat exchanger.
Warning in all RV Furnace manuals:
RETURN AIR
The return air passage should be clean and clear of
obstructions and meet the minimum square inches as
specified in the installation instructions. Make sure
combustibles are not stored in the furnace
compartment. Filters are not recommended at these air
passages.
That minimum is typically at least 55 sq. inches
Always meet minimum return air requirements
