Sewer Tank Flusher

[Doss]

We are getting ready to take our Fifth Wheel on our first trip.
I have a water inlet that says this on it:
CAUTION
SEWER TANK FLUSHER
Sewer tank valves must be OPEN when using this inlet.


OK, I have watched videos on YT about flushing the black tank. They seem to recommend using an inlet to fill the black tank so you get a big flush after the initial dump. To do that, you would have to be letting water in that inlet with the valve closed.

What say you guys?

[Greentow]

I'm right there with DAN-NICKIE. No more than 5 minutes, depending on the water pressure at hand.

[Heavy_Metal_Doc]

I have never understood how a flusher could rupture a tank which is vented. Aren't all RV's black tanks vented to the roof? Not saying SOMETHING didn't cause a tank to rupture, but I would expect overfilling would just send nasty water spewing out the vent and possibly some leaking from the toilet.

Personally, I close the valve for 2 or 3 minutes while the flusher runs. I just watch my level by the indicator lights and double check by looking down through the toilet and then go out and open the drain when it's 3/4 full. I know the spraying of the flusher knocks material off the side walls, but then you need volume of flow to actually carry it away down the drain, especially on shallow depth type of tank as is common to most RV's.

[JWRoberts]

I've been RVing for 25 years and have never found a need for one. As others have said here, wait until the BW tank is at least 3/4 full and then close your GW valve. When the GW tank is at least 3/4 full, drain the BW tank first, then the GW.

[EsoxLucius]

My internal black tank flush does not work without a 55 psi pressure reducer. The integral backflow preventer engages to stop flow with higher pressure.

[Veebyes]

Turn the flusher on before dumping. Leave it on during the whole dumping process. Leave it on for a bit after closing the valve. Always travel with a few gallons in there to slosh around.

[thestoloffs]

dodge guy wrote:

skytrash wrote:
do you use a pressure reducer on your black tank flusher?

No! That would defeat the purpose of the flusher. You want the pressure to break anything up!

But, you DO want to put a backflow preventer (AKA vacuum breaker) on the line, to prevent any black tank outflow from entering the clean water system!

[mgirardo]

dodge guy wrote:
I installed one. I drain the tank, run the flusher, then close the valve and let the tank fill (I can hear when the spray head is under water because you don`t hear it hitting the side of the tank). open the valve and let it drain. very easy, but yes you do need to remember it is on!!!

This is what I do. I generally fill the tank 2 or 3 times after dumping the tank. I've been doing this for over 6 years without issue. Knock on wood, I've never forgotten that I turned on the tank flusher yet 🙂

-Michael

[dodge_guy]

skytrash wrote:
do you use a pressure reducer on your black tank flusher?

No! That would defeat the purpose of the flusher. You want the pressure to break anything up!

[skytrash]

do you use a pressure reducer on your black tank flusher?

[Lynnmor]

Horsedoc wrote:
Help me here folks. With a tank vent coming out the top of the RV, how is it possible to pressurize a black tank by filling it? I understand what you are postulating, but somehow I have my doubts. As the water comes in, the air should come out the top shouldn't it?

You are correct, however the vent pipe is often installed incorrectly with the pipe resting on the bottom of the tank. It's much faster to build when they just shove the pipe in till it stops and then cut it off.

[Horsedoc]

Help me here folks. With a tank vent coming out the top of the RV, how is it possible to pressurize a black tank by filling it? I understand what you are postulating, but somehow I have my doubts. As the water comes in, the air should come out the top shouldn't it?

[Ron3rd]

path1 wrote:
Seems everybody watches it run out.

That must be the exciting part:B

Especially if you have a clear elbow.

[azjeffh]

MWJones wrote:
Path1 said you might rupture the tank if you get distracted. NOT might BUT it WILL RUPTURE THE TANK. Just ask me how I know:o

Not necessarily true. Using my Flush King, I have on 3 occasions overfilled my black tank (after several rinses) and had water overflowing thru the vent pipe on the roof. Same thing happened when I overfilled my galley. Never had a tank rupture or water overflow the toilet or kitchen sink.

Now while I do not recommend doing so, it does not mean you WILL rupture a tank should you do it.

[dodge_guy]

I installed one. I drain the tank, run the flusher, then close the valve and let the tank fill (I can hear when the spray head is under water because you don`t hear it hitting the side of the tank). open the valve and let it drain. very easy, but yes you do need to remember it is on!!!