[rames14]

The 2004 doesn't have the switch between power fill and city water as the newer ones do (we had a 2005 3400rl). I agree with Tim43 that the bypass valve is a likely culprit. Listen for the pump sound and there should be an access near it. I'm not quite sure about the 2980, but it may be under the kitchen sink area. There are two valves. One will be the hot water bypass (also check that to make sure it didn't get left in position when winterizing also). The other one should have a hose connected near it that goes in the pink winterizing solution bottle. Good luck and keep us posted. If that isn't it, then you will already be in the right place to look or air leaks from a loose clamp.