Black Tank Flush??


Well-known member
Do all the Bighorns come with the "Black Tank Flush"??
Is it called something else in the Docking Station?
I have a 2008 Bighorn 3055RL and when I dump after the
Black Tank is full the indicator lights says it is still 1/3 or
1/2 full....I am pretty sure I need to flush her out...
What cha think......

thanks charlie


Past Michigan Chapter Leader
Charlie, I don't have a 2008 model, but it was standard on the 2006 models. In the docking station, it is shown as San-T-Flush and is a female hose coupling.

Don't worry about the monitor. I drain mine and run the flush for several minutes and I still show 2/3 full, but can still get six days out of it before it needs to be drained.


Well-known member
Thanks Guys (and Gals)

I have found my "Black Tank Flush".....
Now I need to figure out how to hook it up
without unhooking my city water every time...
(maybe a tee with a ball valve or something)...ya know...



Active Member
We use a "T" at the spigot, and a DEDICATED hose to "Black Flush Tank" as it can washback into the hose.


Well-known member
There is a vacuum breaker and a one way valve in the line going to the Black Tank. When you disconnect the hose, you will usually get a stream of water (clear) coming back at you. It will be as clean as the hose that you put it through going into the flushing connector. I use a quick connect/disconnect on mine. It is a lot faster and easier to connect and disconnect. I also disconnect the hose from the faucet first to keep from getting the water in the UDC.



Well-known member
We use a 'Y' adapter at the spigot. That way we can get full pressure going into the black flush while the other side (drinking water) goes through a pressure regulator and filter. We also use the quick disconnect in the UDC. It's much easier than trying to get the connection tight every time in a confined space.


This thread is very relevant to me today..
I made my very first flush of the Black Tank on my new 3400. I use a Y on the shore water, then a Watts adjustable regulator, then a water filter and the freshwater hose to my city water connection. I connect a black water hose to the Y opposite the regulator and connect it to the black water flush with a quick disconnect, as jpmorgan37 indicated. This is the reason for a good brass Y with cut off valves. I can then add a water hose for any reason with out disconnecting my city water line. It also allows me to relieve the pressure on the city water when disconnecting.

I have a question for those with Bighorn experience. When you connect the black water flush and turn on the hose it makes one heck of a noise. Also should this hose be connected to the regulated water or the shore source at full power. I was assuming that the hose went into the black tank and used a device to spray water all around the black tank. It seems to me that the water line is going through a wall by the toilet. This thing is really loud.

When I drained the tank and the sensor showed it was still 2/3 full. I know it wasn't. Ran the black water flush a number of time until the water looked pretty clear. Each time I ran water until the sensor showed a rise in the tank. Then I emptied the tank. When I finished the sensor showed empty.

How do the rest of you flush your black tank?

Travel Safe and God Bless


Well-known member
I usually run my flush for about 10 minutes, and yes, it does make a noise. The vacuum breaker and check valve on my unit is behind the closet at the front door next to the toilet about 4 feet high. Usually the output from the tank is clear when I finish my flush.