On this page: tanks (gray & black), Water Pump Switch, tank maintenance, macerator, dumping, articles
Also see Bathroom / Toilet
Tanks
• The gray tank holds the sink and shower water. MP107
• Gray water tank capacity 23 gallons/ 85 liters MP80
• Galley sink, bathroom sink and shower drain water drains into the gray water tank. MP48
• The black tank holds the toilet waste. MP107
• Black water tank capacity10 gallons/ 38 liters MP80
• Close both the black and gray water gate valves before using the waste water system. MP7
• Close both the black and grey water gate valves before using the waste water system.
It is possible for the valves to open slightly especially after extensive driving. Black and
grey water dump valves are accessed through the driver side storage door. MP49
• Under moderate subfreezing conditions, antifreeze is required in the exterior fresh water tank, black and gray waste water
tanks. Use RV antifreeze in accordance with the manufacturer's instructions.MP7
See Monitor Panel for Water Pump Switch
• Indicators - The gray and black water tank level indicators on the control panel will give you an approximate indicator of your
tank level MP48
Tank Maintenance
• At Least Every Three Months MP74
• Flush black water holding tank. Use a hose or bucket to fill the tank through the toilet, and dump.
• Flush grey water holding tank. Use a hose or bucket to fill the tank through the galley sink, and dump.
• At Least Twice A Year
• Inspect black water tank vent and remove any debris or other obstructions. The black
water tank vent is on the roof, passenger side, in the bathroom area. MP76
• Holding tank odors
• RV Tech Tips from Mark Polk One secret to controlling odors and extending the life of your RV holding
tanks is to add plenty of water to the black water tank every time you empty it. You want the bottom of the
tank to be completely covered by water, and depending on the size of the tank this might require three
toilet bowls of water or it might take five or more. Another thing to keep in mind is to add plenty of water
to the bowl every time you flush the toilet so there is enough water in the tank at all times to help control
holding tank odors. Mark Polk is the owner of RV Education 101, the premiere source of educational
DVDs about buying, maintaining and using an RV.
• We also use something called the “Geo Method.” Essentially, this mixes two cups of water softener and
one cup of household detergent in a gallon of water that we pour down the toilet after every time that we
dump the black tanks. It really helps keep odors down. We use Calgon Powdered Water Softener. It
supposedly dissolves the fastest. We had trouble finding it in stores and ordered it on Amazon. They make
a liquid version of this product. It may work, too, though the person who told us about this stressed that
we should use the powdered kind. Roadtreking.com
• Sometimes, gunk gets caked on black water tanks after a lot of use, especially if the unit hasn’t been
used much. If you suspect that is an issue, buy a bag of ice, drop it down the toilet and drive around for a
while. The ice bangs around in there and loosens the crud. After you think the ice has melted, flush with
lots of water and then dump.Roadtreking.com
Macerator
• SHURflo Model 3200 Macerator Pump Manual in .pdf
• SHURflo’s macerator pump is designed to empty marine and RV holding tanks of normal waste. Manual
• When tank is empty, pump will get louder with a high pitch sound. Immediately turn pump off, or damage to impeller and
housing will occur. Do not run pump dry for more than 15 – 20 seconds. Flush tank and pump with water after each
use. This macerator will handle normal waste, tissues, cigarettes, fish scales, etc. It is not designed to handle large hard
objects such as large bones or fruit pits. Manual
• Articles
• Living in the Roadtrek - Dumping the Waste Tanks, Meryl and Me Hit the Road; and Me Hit the Road
• Re: MACERATOR Mon Dec 14, 2015 4:41 pm (PST) . Posted by: levercjames - When you are done, the norm is to mix a
1/2 gallon or so of treatment water and put it in the black tank. Do that, but make it more like 1 gallon of mix. Once you have
the solution in the tank, pull the black dump valve to get the pump full of treated water, and close it when it quits glugging. That
will keep the pump from drying out and getting stuck, which can rip off the vanes of the impeller. It makes sure it has good
prime and lubrication at the start. Any residual "stuff" in the pump will be exposed to the digester in the treatment. When we do
it this way, we easily have been able to see a difference at the start of the next pump out, which is quieter and gets liquid out
the hose faster and smoother. This all came about when we noticed that many folks who use their pump a lot, didn't have
issues, while folks that use them less often seemed more likely to have an issue. It certainly makes sense.
• Holding tank tips for the stationary RV
...In really tough situations you may need to fill up the holding tank with water, dump it completely, and then add a couple of
cups of baking soda and fill it up with water again. This time don’t dump the tank immediately; let the tank sit overnight, then
dump it and “restart” the system with the addition of a bacterial and/or enzyme based holding tank treatment.
Waste Water (Gray and Black) Discharge Pump / Macerator
• MP108
• The macerator in this pump grinds up any solids in the system and pumps the resulting wastewater out to the dump station.
MP10
• If possible, you want to dump the tanks after driving as the movement of the vehicle will have sloshed the water in
the tanks, loosening any solids. MP108
• See DAILY START FOR DUMPING WASTE WATER and Jammed Macerator MP113
Articles
• Are you dumping your black tank correctly? RV Travel June 13, 2018