2015 Chateau 31W Furnace issue

[woodworker414]

Good afternoon.
I was laying in bed this morning and heard the furnace kick on. Starp operation, fan comes on to purge, then the flame ignites. Today it do that and burn for a short time then the flame would go out, and repeat the steps 2 more times then go into falult mode. I would turn off the furnace at the thermostat, and turn back on. It would to the same thing. It will not stay lite. It worked 2 weeks ago when it was cool. I have a full tank of propane. I checked for the fault code, the blinking light. I don't have a blinking lite on the board. It is a:
Atwood
hydro flame
8500-IV series
with various model numbers.
Does anyone have any idea why this is happening?
Any thoughts would be appreciated.
Thank you