You should have received a whole packet of user manuals . . . a generic Heartland handbook that covers all the trailers in general terms and then specific manuals, instruction sheets, and warranty information for all the appliances installed in your rig (e.g., A/C, furnace, stove, microwave, etc.).
There is no manual that is specific to each model. If you did not receive such a packet, then you should first contact your dealer.
On edit, Oops, looks like Dan was typing a response at the same time I was. Sorry this is redundant.