Water... Where it comes from... Where it goes....

Everyone has to deal with water every day. Getting it for washing, toilet, cooking, watering lawns etc. and living in an RV whether part time or fulltime does not change that.... or at least not the need.

I thought it was about time I summarized how these things happen in an RV (or at least Ginny thought it was about time....)

Water In:
Starting with the water in we need to fill the fresh water tank that is mounted between the frame rails of our motorhome. It is 89 gallons. With prudent conservation we can go a week on this amount of water and with strict conservation we can probably go 2 weeks.

On the passenger side of the RV there is a small access door that is locked (to guard against some treasure of humanity pouring something bad in there). This is where we can pour water into the tank.

This would be by jugs or water cans or buckets or any other container that is not under pressure. We never use this one to fill the tanks however, it is strictly for an additional option.

The primary way we fill the tank is by the water hose. This hose in on an electrical recoil reel.
(see on the left)

You pull it out manually and retract it electrically by holding down a button on the reel. There is a valve that has 2 positions. "Water Fill" and "City Water". (to the right of the shower head) After the hose is connected to a faucet under pressure we place the valve into the "Water Fill" position and the water will flow into the tank. We have to manually turn the water off when full or switch the valve to the "City Water" position which is to supply water to the "house".

If we are in a campground

or at Mom's house we have the valve in the "City Water" position. Then the sinks and shower and toilet work just like a "sticks and bricks" house.

If we are without a water faucet to connect to there is a water pump that pumps the water to the fixtures.

Hot water is achieved with an RV water heater. This water heater has a 10 gallon tank, some are 6 gallon.

Ours heats by using LP from the RV's LP tank OR by using an electric heating element. We can heat the water even faster if we utilize both the LP burner AND the electric heating element.

Water Out:
After we use one of the 2 sinks, the shower or the toilet, the water and etc. go down a drain. The toilet is a separate drain system. The toilet itself is different from a "sticks and bricks" toilet. With an RV toilet there is no tank mounted above the toilet for flushing. Instead the toilet has a foot pedal that, when depressed, opens a valve to allow water to come into the toilet from the fresh water tank under pump pressure if we are not connected to a campground faucet or under the campground faucet pressure without our pump. The toilet foot pedal has 2 positions. Depressing the pedal half way allows the water to enter the bowl and circulates and washes the blow walls and fills the bowl until the pedal is released. If you press the foot pedal fully the water enters to wash the bowl AND the bottom of the bowl opens up to a pipe going straight down to the "Black" tank.

The black tank is strictly for the toilet drain.

The sinks and shower drain to a "Gray" tank. This gray tank is separate from the black tank. So to summarize the tanks there is an 89 gallon fresh water tank, a 52 gallon black tank and a 48 gallon gray tank.

When the tanks are full or when we want to dump them we hook a 3 inch hose from the RV to a septic tank at a campground or a water treatment plant or other appropriate place always keeping in mind that it is necessary to dump the black tank and, for the most part, the gray tank in an environmentally and neighborly way.

Some bad guy RVer's have been known to dump in the wrong place out of laziness or stupidity. (Ever seen "Christmas Vacation" with Chevy Chase?)

We fill the gray tank much faster than the black tank and when it gets full we have devised a method to transfer the gray contents to the black tank. We added an extension and an additional valve with a clear pipe section to the RV dumping outlet.

When the gray is full and the black is, say, at 20% full we can connect the gray to the black and then allow physics to move the contents from the higher gray side to the lower black side. The gray will move to the black until the two sides are equal amounts then we close the connection between the two tanks. The results would be approximately:

Before transfer: gray=100%   black=20%
  After transfer: gray=63%      black=57%

Now we can stay where we are a few more days before being forced to find a dumping place to empty the tanks. By the way you should ALWAYS empty the black tank before the gray tank so the relatively clean gray water can clean the black residue from the drain hose.

Every RV is different but the basic method is the same. Smaller RV's have 1 sink, 1 shower and a toilet. Some large ones have as many as 4 sinks (bathroom, 2nd bathroom, kitchen, outside galley) and two toilets and an outside shower (great for washing sand off your feet so as not to track it into the RV). There are other configurations but this would cover 99% of the RV's on the road. A few have a bathroom sink drain into the black tank and some RV's have 2 gray tanks because of the location of 2 bathrooms making it easier to route the drain pipes into a more closely mounted tank.

So in summary.................
water goes into the fresh water tank.
shower and all sinks drain into the gray tank.
toilet drains into the black tank.
3 inch outlet connects to septic system to drain all tanks.
LP and/or electricity heats the water in the water heater.

Other water things:

If you are not a fulltimer and you live where the winter temperatures get low you will need to "winterize" you RV. This is done by turning a valve to bypass the water heater and draining the whole system.

You will want to keep food particles out of the gray tank as much as you can to cut down on possible odors. We use these screens and they work great.

Thanks Ginny for finding them!

Thanks for reading and as always comments and corrections are appreciated.....

Eric