Using the water and toilet system in an RV is similar to your in home system with a couple of very important differences. The key difference is the fact that the RV has a set of holding tanks (one for Gray Water & one for Black Water) designed to hold waste water while not connected to ground facilities. The tank size and plumbing locations as well as components may vary, but the principle is the same. The other difference is the amount of water consumed in an RV versus a home. This is a result of the RV's ability to carry its own supply of water in a separate fresh water tank. When connected to fresh water via a hose, you can use increased volumes of water, however, the water still exits the RV through the holding tanks.

RVers sitting for long periods of time in RV resorts, etc. tend to leave the gray water valve open because it is inconvenient to go outside to pull the valve every few days. This practice leads to future problems with bad odors coming from the tank through the vent pipe. In general, people know enough to not leave the Black valve open for extended periods because the waste will clog the 3" hole and fill the tank! The gray tank will not suffer this major problem, but will share the odor problem.

Until recently, RV manufacturers had to place the slide valves at the sidewall of the RV for customer access. The small valve on the gray water was just not questioned and became standard over the years.

One of the most common design flaws is the use of gray holding tanks with a smaller than 3" drain opening. By using 3" piping on gray water, the tanks are emptied 2.57 times faster allowing more of the build up and scum to exit the tank. With the use of electric valves manufacturers are able to place the valves at the tank outlets which greatly reduces, if not eliminates blockages.

1. Is it equipped with the Drain Master Evacuation system?

2. Are there tank sprayers on both tanks?

3. Are the valves located at the tank outlets?

4. Is the evacuation hose a Sewer Master?