I blew out all my water lines and black water rinse and drained all my low point drains and water heater. Then I got to thinking my water pump is still sitting with water in it. So I had this brilliant idea to use RV antifreeze. Closed all faucets, hooked up antifreeze inlet tube in UDC and inserted it in jug, turned the valve in the UDC to "winterize" and turned on the pump. Pump proceeded to suck my RV antifreeze jug dry and fill my water heater. Not exactly what I had in mind. Any ideas why Heartland wants you to fill water heater with RV antifreeze?