Rickas ,welcome to irv2 with your new coach.
If you check for 12 volts at your furnace location we will know if its ok that far. Also under your refer if thats where your furnace is located you will have a cold air return inside your coach to your furnace, remove the return air grill and maybe wood baffel you may find two more fuses for your furnace,check these also. The grill maybe held on by velcro strips or screws., Check at electic outlet for refer also for 110v, the outlet maybe controlled by a gnd fault outlet in kitchen or bathroom and maybe tripped. Make sure your gas valve is on,where it feeds into your furnace, you will have to remove outside cover to your furnace to gain access to this valve.
Let us know how you are making out so we can follow up for you.

"007"
P.S. When you have time in your sig. profile post your coach and chassis info for future reference, you won't have to keep posting it in the future.