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Which Holding Tank Is Which On My RV?

by Thomas Thompson
(San Diego, Ca.)

I just emptied both holding tanks on my 1990 Fleetwood Tioga RV. On the control panel the system shows holding tank 1 empty, and holding tank 2 full. Which number tank is the black water, and which number is the gray?

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starstarstarstarstar 		Holding tank
by: Anonymous

Rv standards for Holding tank 1 and 2. 1 is grey and 2 is black
Rating
starstarstarstarstar 		Black tank labels.
by: Anonymous

My 2019 keystone 3811ms has three dump valve handles. One grey valve for the kitchen sink, one grey valve for the bathroom, and a valve for the sewer/toilet. There are four labels on the indicator panel. One black tank indicator reads zero always. Must be a universal panel. Confused me at first, now I just ignore the light. The real light shows full all the time. Worked one time. Dump black tank twice a week. Leave grey valves open all the time.
Rating
starstarstarstarstar 		Tank 1 or 2
by: Anonymous

I'm not sure about yours but my RV has tank 1 tank 2 and Black Water tank. 1 or tank 2 is for the kitchen area and then the other tank is for the bathroom area not including the toilet. The trick is finding out which tank 1 or 2 is Kitchen tank 1 or tank 2. because when you drain the grey water you drain both those tanks. You can search PDF manual with your RV make and model maybe that will help you
Rating
starstarstarstarstar 		Holding tanks
by: Anonymous

I have a 1999 dutchmen on our tank levels we have three holding tanks besides the fresh water. Can anyone tell me what holding tank 1,2,3 mean. Thank you so much. I app.
Rating
starstarstarstarstar 		grey tank 1 and 2
by: Anonymous

We have two grey tanks, one for the kitchen and one for the bathroom. Which is #1 and #2
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starstarstarstarstar 		Tank 1, Tank 2
by: AnonymouSteves

The large pipe drain is black
The smaller pipe drain is gray.
But the original question was;
On the panel the switch is labeled "Tank 1" and "Tank 2".
He wants to know is Tank 1 gray water?, Is tank 2 Black water?
I THINK some Einstein labeled Tank 2 black tank corresponding to what is in that tank.
Tank 1 for gray water.
Rating
starstarstarstarstar 		Holding tanks
by: Anonymous

You folks still haven't answered his question... easy way to remember..

When you go #2 that's your sh*tter tank
#1 is your grey water
Rating
starstarstarstarstar 		tank handles
by: Anonymous

I just bought a 1993 tioga and the handles are different the black tank is a large handle while the grey one is smaller
Rating
starstarstarstarstar 		RE: Holding Tank
by: Anonymous

I may be wrong, but I don't think he was asking about the valve. I think he was asking about the control panel indicator. If his are like mine, the control panel indicators are labeled Tank 1 and Tank 2. A real genius came up with that idea. So now I have to wait till I get both tanks full and empty one and look to see if tank 1 or tank 2 is empty, then label them. My dealer didn't even know. Never buy anything from a dealer. Stupid is as stupid does. I think I'm him sometimes.
Rating
starstarstarstarstar 		GRAY TANK / BLACK TANK
by: Papatony

I have no idea which tank is which on your rig, but you can figure it out, just the way I did when we bought a used travel trailer with no manual:
Assuming both tanks are currently empty, at an appropriate location,
1. Connect the sewer hose
2. Open ONLY ONE of the tank dump valves
3. Run water in one of the sinks
4. Check to see if water is running out of the "stinky slinky"

If water runs out of the sewer hose while you have the sink water running, label the tank valve you have open as "gray". Obviously, the other tank should be labelled "black".

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