Hi blong,
I've attached some marketing info. As far as I know, Heartland hasn't published specific usage instructions.
Operation is pretty simple. All installations have a switch that controls the tank heating pads. When temps go below freezing, you need to turn the tank heaters on. BUT, you have to have at least a little water in the tanks to dissipate the heat. It's possible to damage the tanks by running with tank heaters ON with empty tanks.
The heat tape is on the fresh water line between the fresh tank and the pump. Again it should be ON in below freezing temps and there should be water in the line (run the pump until water comes through a faucet).
On some builds, the heat tape is turned on with a separate switch. On some builds (prior years I think) it comes on automatically based on a temperature sensor.
The tank heaters are 110V and only work on shore power or generator power. The heat tape on the fresh water line is 12V. One thing to be aware of is that if you're running on battery power, the heat tape will draw the battery down quickly.
For other cold weather tips, take a look at our owner-written
Water Systems Winter Usage Guide.
View attachment Yeti.pdf