My Atwood 8500 furnace will not light

[Pedecanada]

Was just trying out furnace on new to me 2009 airstream and furnace will not fire. It did work a couple times but today would not at all. It would start and stop fan really fast about 3 time and on fourth try fan would keep running longer but no igntion or ignition noise then shut off and light would flash on circuit board one flash every three second. The manual says light means there is limit switch/airflow problem. Where is air sucked in for furnace is it under fridge and sucked in from top of heater box. If it is there there is a crazy amount of dog hair under there from previous owner dog I take and how would I clean out intake. Thanks for any help.

[TG Twinkie]

The furnace draws it's combustion air from outside. Go outside and you will see two holes in the side of the trailer where the furnace is located. One is the intake (fresh air) the other is the exhaust. Make sure neither is blocked. Mud daubers build there nests and lay eggs in the intake and exhaust ports. It may be necessary to clean out the tubes.

[Pedecanada]

Thanks for hint I will check. It seems like there is alot of dog hair and lent under fridge like there is air moving under it for furnace or it might be caused by outside air vent being pluged.

[Pedecanada]

I did the hit left corner of heater box to dislode switch and it worked five time after no problems. This fourm is great help.