San-t-flush question - RV-Dreams Community Forum

dmorse68 · RV-Dreams Community Member

San-t-flush question

LarryW21 · RV-Dreams Family Member

On my TT Winnebago recommends never closing closing the valve...but I do for short periods.

NorCal Dan · RV-Dreams Family Member

I used to close mine and let the tank fill half way with water before opening the drain. I think the real reason they recommend not closing the gate valve is because of the consequences if you get distracted...my motto was "one task at a time"...

Howard · Host

I agree with Dan. The main reason they don't want you to close the gate valve is because if you do so and get distracted you can flood your rig. Pretty much every rig's owners manual tells you to leave the gate valve open when backflushing.

I haven't heard the "pressure build up" thing, but it certainly shouldn't "blow fittings". It probably isn't good for the "spinning head" to be underwater, but I wouldn't count on that spinning head working for very long anyway. I've known way more "spray-type" flushing systems to fail than to last any significant time. The main thing is that you can get water into the black tank.

And, for what it is worth, most of these have a "check valve" at the connection that often fails. The check valve is designed to prevent water that has gone into your RV from coming back out, but sometimes they freeze in cold weather or fail for other reasons. If you find that you disconnect the hose, and water comes back out through the connection, chances are your check valve has failed.

Terry and Jo · RV-Dreams Family Member

David,

We also have a Mobile Suites, and I close the black tank's valve for at least 2 1/2 minutes at a time. I first pull and dump the tank and then open the valve at the hydrant to the flush system. After letting it flush for about 5 minutes or until the water coming out is clear (I use a 6" clear sewer extension to see the water), and then I close the tank valve for 2 1/2 minutes followed by opening the tank valve again for another 2 1/2 minutes. Water is generally clear by then. As the others have stated, the precaution of NOT closing the valve is primarily to prevent a back-up into the toilet and overflowing.

Our Mobile Suites is a 2010 and the line from the San-T-Flush goes to the end of the black tank on the door side of the coach so that it is spraying towards the discharge side of the tank. I don't think our tank has a "spinner."

Terry

Cummins12V98 · RV-Dreams Family Member

The "TECH" simply put is an idiot! Basic RV construction, the tanks are vented thru the roof, he should know that. If they were not the tanks would be VERY slow to drain.

After letting most of my black tank drain while having my flush running I close black tank valve and set the timer on my phone for 8 minutes and place in my POCKET. Timer goes off I open valve, once most of the water flow is gone I close and set timer for 8 minutes again. Timer goes off open tank valve and once its down to a slow flow of clear water I close tank valve and then turn off flush. This allows a couple gallons or so to stay in the tank. Been doing this method for many years and have never experienced the "poop pyramid".

RonC · RV-Dreams Family Member

Cummins12V98 wrote:
The "TECH" simply put is an idiot! Basic RV construction, the tanks are vented thru the roof, he should know that. If they were not the tanks would be VERY slow to drain.

After letting most of my black tank drain while having my flush running I close black tank valve and set the timer on my phone for 8 minutes and place in my POCKET. Timer goes off I open valve, once most of the water flow is gone I close and set timer for 8 minutes again. Timer goes off open tank valve and once its down to a slow flow of clear water I close tank valve and then turn off flush. This allows a couple gallons or so to stay in the tank. Been doing this method for many years and have never experienced the "poop pyramid".

X2 ... I follow this exact process. One tip, after you close the black tank valve, take a moment to ensure the water flow out the drain STOPS. If it does not, you may have a failed valve seal, which would allow the water to leave your tank but not the solids ... not a good thing. Ask me how I know this😉