I just purchased a 2010 305 Road Warrior and when watching TV and using the Jensen Power 760 the TV sound uses the AV in-1 setting on the radio (jensen dv2007). I kept noticing a hum in the ceiling speakers only, that comes and goes, I have now discovered the humming starts when the hot water tank lights and continues until the hot water tank shuts off. Does anybody know of a line filter that could stop the humming. Or another way to stop this annoying hum? It does not hum through the speakers on the TV. Thanks!