If its brand new & you just accepted delivery, you really have no idea where the water in your fresh water tank was sourced. You can hope for something simple, drain the tank and refill, if that doesn't solve it, go through the sanitizing process.
New or used, it's the same process. I periodically pour some bleach into the water hose, and then run that bleach and some water into the tank. Also, we don't drink the water from the fresh water tank.
PS. Once you are off the road, beer and wine always taste good!
There are friends, there are family, and then there are friends that become family!
Even after sanitizing the water system 3 times, it took more than a year for our water to not have a "plastic" smell. We do not drink water from our fresh water tank or from a city connection. I do have a water filter that I use when connecting to city water. I do use it to rinse after brushing my teeth; however, my wife (a retired RN) only uses bottled water for any internal use.
Ed & Bev Felker
Retired USAF Col and retired Nurse
Traveling with Lily & Bella ('Teddy Bear' breed)
2015 Vegas 24.1 (E-350)