The great thing about driving around with a house behind you is that when you need to wash your hands, you have an on-board sink. In the ERA, you have 2–one in the galley and one in the head. In the ERA, to dispense water from the faucet, one must turn on the water pump. The water pump fires up, pressurizes the tank, forcing water through the conduits, and once a certain level of pressure is reached, turns off. There is built in hysteresis so that the pump is not constantly cycling on and off.
As you may recall, a couple of days ago I had an issue with right front tire. When checking the right front tire at the local gas station, which at the time, unbeknownst to me, had a self tapping screw in it, my hands acquired a nice coating of brake dust. No problem. All one need do is turn on the water pump and wash your hands in the galley sink, which is what I did.
Now, the ERA shower is attached to the sink in the head, and one must pull up the plunger valve on the faucet to activate it–there is also a switch on the shower head itself. So one can cut off the water to the shower head in one or both places. If you leave the shower head switch open, the plunger valve at the faucet can still be closed to keep water from coming out of the shower head.
The freshwater tank in the ERA holds more water than the gray water tank in the ERA. And together, the gray water tank and the black water tank hold more water than the freshwater tank. We are special people, so we never use the blackwater tank. If one were to empty all of the freshwater tank into the gray water tank alone, the gray water tank, not having the capacity to hold all the freshwater, will overflow. The overflow water has to go somewhere. Luckily, it is held by the shower drain pan. It will not flood the coach. We found that out the hard way. It was Caprock Canyon all over again.
After washing my hands after checking the tire pressure, I did not turn off the water pump as it had built up enough pressure so that there was no noise to alert the user that the pump was still on. Fine, as long as all the faucets and valves are all closed, no problem. But if the shower head switch is open, and the plunger valve on the galley faucet is closed, it does not take much bouncing down the road for the plunger valve to go down, thus opening it, thus allowing the water pump to cycle all your freshwater through the shower head and into the gray water tank, which as noted, has less capacity than the fresh water tank. We averted disaster as the shower pan held all the excess water. Lesson learned: Always make sure your water pump in the ERA is off when not using the fresh water.