I feel a little ridiculous asking this question, but am new to all of this so here goes. I purchased a used Forest River 2011 Wildwood Heritage Glen 5th Wheel Trailer - Model # 246 RLBS. The question is where is the furnace access and check the burner flame through the burner observation window? do I have to remove a panel to find this? Any information or help on this would be appreciated. thank you.