05-05-2018, 09:39 AM
Our coach has 2 12v pumps. Selector switch runs only one at a time. We hook up to city water when we are going to be stationary for a few days or if we need to run washer/dryer. One thing I have found over the years is that when on city water, if there is a water shut off for line service on the city side, if the 12v pump is on, it will empty the fresh water tank a keep on running until you shut it off. Also, city water pressure is usually high enough to keep 122v pump from running if it is left on. We keep a regulator set at 40 psi on the "city" end of the hose when hooked up to city water to keep from over pressuring coach water system. We also usually top off fresh water tank when we unhook from city water to make sure we have plenty of water for showers etc when traveling. Dumping black tank to make sure it has room for all the water is also done at the same time. Forgot to do that one year before going to Quartzsite to boondock for 10 days. Had plenty of fresh water but ran out of black tank capacity to put it in.