Michael I would be careful leaving the frig. on for extended periods. I own a 1998 H-410 and left mine running most weeks between my weekend visits. My "water-cooled" Grunert unit ended up buring up the water pump because the filter became "mucked" up. Granted, weekly checks of the filter might have avoided this $230 problem. Although an air-cooled unit would not experience this problem; electrical outages, and other concerns, I believe cut against leaving it on.Norm