Preheat Switch: On our '98 Patriot, this switch does only one thing; namely, it turns on the coolant circulation pump for the hurricane system and pumps(circulates) the water in the system throughout the coach. If you want coach heat, you still have to follow the procedure mentioned above, of setting the main control. We use this feature a lot when traveling in chilly weather.
Also, on our coach when this switch is on the pump is on, so be aware you are pulling several amps from your coach batteries full time. That is fine, if you are plugged into AC or the Generator is running, but you may not want this switch on when parked, unless you have something charging your batteries, especially when it is cold.
We also always have the preheat switch on during travel, so the system is hot and ready when we park.
Larry Fritz
Adams, NE