Furnace Vent
The answer to your question is "Yes". There should be a furnace vent for every model we produce. It should be right on the cabinet that houses your furnace. This helps the air flow tremendously. If your coach does not have this, we need to get you into the dealer and have one installed.
You can contact Randy or Chris at Heartland's Dealer Services (New phone: 574.262.8030) and have them set it up with your dealer.
I apologize that this was overlooked at the factory, and we will get it rectified quickly for you.
As for the invertor buzzing, I am not sure about that one. If you call the Progressive Dynamics number in your owners manual, their technical service people can help you. If it is a problem, they will send a new one out and pay to have it installed right away.
ST