Interesting problem I ran into this past weekend. After getting home & plugging in my 2007 Fleetwood Williamsburg Popup to 120V to keep the battery charged I did not notice that the water pump kicked on. It ran almost 24hrs with no water. The popup was closed up which meant the Galley Kill switch was dis-engaged. The water pump switch was on. On my 2000 Coleman Destiny when the Galley Kill Switch was dis-engaged (i.e. being stored) the water pump never turned on when plugged into 120V - not even if the Water Pump Switch was on. Some water pumps are lubricated with water and running them dry for prolonged periods will damage them. TBD if the pump burned up but will check in the next couple days.