Airstream CLASSIC TRAILER Owner's Manual page 74

PLUMBING
Monitor Panel
Check your monitor panel frequently. When the BLACK WATER HOLDING TANK is
completely full, sewage cannot be emptied from the toilet bowl. If the GRAY WATER
HOLDING TANK is overfilled, drain water will "backup" into the tub and cause an
unpleasant cleaning job. Never drain the tanks at any place other than an approved
dumping station.
Emptying Tanks
Almost all campgrounds will have dumping facilities. Park directories such as Woodalls
and Rand McNally also list dumping stations.
To empty one or both tanks attach the sewer hose by pressing the bayonet fitting onto
F
the dump valve outlet and rotate clockwise until it feels solid and secure. Attach the
outlet end of the hose to the sewage outlet; making sure that the hose is placed so it
will drain completely.
Pull the dump valve handle as far as it will go and wait until the tank is drained. When
dumping, the main holding tank should be dumped first; then the auxiliary holding
tank. This will help to rinse out the sewer line with auxiliary holding tank water.
The main holding tank must be flushed out until all paper and waste material is
removed. Close the dump valve and refill the tank with clean water and repeat until
clean. Replace the cap prior to traveling.
The main and auxiliary tanks are heated by ducting from the furnace. Be sure to follow
winterizing instructions for the tanks immediately in freezing temperatures if heat is not
being supplied to the trailer.
Black Tank Flush
Inside the underbelly utility compartment is a water hose connector for the "black
tank flush". To use, hook up a hose and turn it on full force. Within the tank a head
with multiple holes will spray the interior surface of the tank. A vacuum breaker and
one-way valve is located inside the trailer above the exterior connection to prevent the
black water from escaping to the hose connection. In most models this will place them
under the lavatory.
The gate valve should be closed for the first couple of minutes, and then opened to let
the water out in a rush. Close the gate valve and repeat as needed.
When Parked and Connected to Sewer Outlet
When you are in a park and connected to a sewer outlet keep the main holding tank
dump valve closed, and empty the tank every few days or whenever it becomes
almost full. ONLY BY SENDING A LARGE VOLUME OF LIQUID THROUGH THE MAIN
HOLDING TANK AT A TIME WILL TOILET PAPER AND OTHER SOLIDS COMPLETELY
WASH AWAY.
This practice will avoid the accumulation of solids in the main holding tank, which
could lead to an unpleasant cleaning job. Should solids accumulate, close the dump
valve; fill the tank about half full with water, then tow the trailer for a few miles. The
turbulence and surging of the water will usually dissolve the solids into suspension
so the tank can be drained. Keep the auxiliary tank valve open when connected to a
sewer outlet.
Draining the tanks as described will protect them from freezing during storage. When
traveling in sub-freezing temperatures use a winterizing solution designed for RV use.
Follow the directions on the container.
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