Chris Bryant wrote:
No, it isn’t. Check the ducting for blockages or recirculating hot air. It is never good for it to cycle on the limit switch.
Also, you need the install specs for your model furnace. RV furnaces require the correct amount of duct tube knock out plates in use to prevent overheating. Your furnace is overheating and that is what is causing the burner to short cycle. There are 2 ways a furnace is ducted and BOTH may be utilized at the same time.
1. 4 inch round knock outs with 4 inch duct tubes
2. THRU the floor ducting which the output of the furnace on the BOTTOM is forcing air thru a in the floor duct system.
Last, it is not a good idea to cut off or restrict a duct to stop heated air from causing an area to get too hot. THAT will restrict and cause burner short cycling also. Doug