NanciL wrote:
I had the same thing and it was a defective check valve in the water pump, allowing the water to flow back from your city water pipes.
jack L
In my case, since I don't use the fresh water tank, I disconnected the outgoing pipe from the water pump and installed a valve in it and then just keep the valve off.
Since the trailer is still under warrantee, I brought the water pump into the dealer and told them the check valve in it was defective. Naturally they said they had no means to test it and would have to send it back to Forest river. Two weeks later they called and I now have a brand new replacement, that I will probably never hook up.
Jck L