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Plumbing Systems
Your RV plumbing consists of two primary systems: Fresh Water (potable) and Wastewater. Each
system has its own holding tank(s) including a fresh water holding tank for clean potable water while
camping away from city and park water connections and black and gray waste holding tanks for
containing body waste and drainage from sinks and bath shower. Black and gray waste holding tanks are
independent of each other and are not interconnected other than sharing the primary drain outlet.
Typically rear kitchen model RVs have (2) gray holding tanks, one for the kitchen sink and one for bath
(shower and sink).
Many of the RV plumbing system components are identical to modern residential plumbing components
and function in the same way.
FRESH (POTABLE) WATER SYSTEM
Fresh water is supplied to the RV system by two alternate sources.
1) The External Fresh Water connection (city or RV park water).
2) The self-contained On-Board Water Tank.
~ Prior to using the Fresh Water System it is recommended that the entire water system be sanitized,
drained and flushed. See 'Sanitizing the Fresh Water System' in this chapter for details.
External Fresh Water Connection
It is highly recommended to purchase a 'Drinking Water Safe' RV specific freshwater hose as well as an
in-line water filter and in-line pressure regulator for this water supply. To use the external water system,
first connect the water hose to the potable water source, then to the hose connection on the driver side or
rear or your RV. Fifth wheel models may be located inside the water center compartment on the driver
side. Be sure to run the water for a few seconds to clear the hose from any debris before connecting to
the RV. The water pump design is such that it will prevent water from this connection entering the on-
board water tank.
The RV water pump should be turned off while the RV is connected to city or park campground water
source. Since the city or park water source provides its own pressure, the water pump is not needed.
IMPORTANT: EXCESSIVE WATER PRESSURE. Some city or
campground water systems may operate at pressures that can
damage the water system in your RV or cause water pump failure. If
pressure at your site is over 70 PSI, you must use a pressure
regulator. The recommended pressure range is 35 PSI to 45 PSI.
Your RV supply dealer can advise you on the best choice regarding
water pressure regulators.