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Topic: Vacuum Toilet Protocol (Read 560 times) previous topic - next topic

Vacuum Toilet Protocol

All of my many years RV experience has been with bomb drop toilets.  I have always abided by the procedure of keeping the black valve closed until ready to dump with at least half a tank. 

I was asked for advice by a lady with an sob coach which has vacuum flush system about whether to leave both the gray and black valves open full time or keep the black valve closed until half full or more.  My first reaction was to advise to do as I have always done.  After thinking about it I realized that maybe the vacuum systems are different. 

So my question for those with experience; Is it normally acceptable to leave the black valve open full time if you have vacuum toilets? 

Thanks
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
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Re: Vacuum Toilet Protocol

Reply #1 –
We have the Sealand, (Dometic) VG2 vacuum generator toilet setup. We don't leave any waste valves open until dump time. I don't think there is any requirement to have the waste valves open. The VG unit is a separate subsystem, once waste is evacuated from the toilet and cassette it's deposited into the black tank.I assume the black tank is vented, as we've had no issues with pressure buildup with waste valves closed in use.

I believe there is an advantage to allowing the tanks to fill up. We have the third Valterra waste valve installed and use it to backflush the black tank with the gray water tank. This allows you to flush more of the solids from the black tanks.

It works great, does need to have preventive maintenace performed about every 2-3 years, replace the four duckbill valves and the toilet ball seal. 

Jeff
Jeff & Kristen
2002 U320 build #6039
Living the Dream!

Re: Vacuum Toilet Protocol

Reply #2 –
Why does the term "vacuum toilet" system bring to mind the image of the vacuum canister delivery system at our bank driveup?
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Vacuum Toilet Protocol

Reply #3 –
Vacuum toilet systems are popular on large yachts with holding tanks. To  complicated imo. And costly.
'99 U320 40 WTFE
Build #5462,
1500 Watts Solar 600 amp Victron lithium
2012 Jeep Grand Cherokee Overland Hemi
Instagram bobfnbw
Retired

Re: Vacuum Toilet Protocol

Reply #4 –
Quote from: nitehawk –
Why does the term "vacuum toilet" system bring to mind the image of the vacuum canister delivery system at our bank driveup?

Because it is exactly the same system!  Took me YEARS of dealing with the Sealand Magnum Opus Turbo Turd 3000 and it's extravagant circuit board and extenuating issues before I finally found a guy who knew what he was talking about. The vacuum  system is not an issue if you keep the maintenance up.  We always ran off the onboard water tank. When you need to fill fresh water, then dump the tanks. Backflush the black with the grey, use the tank flush to rinse, and Bob's your uncle.  I never used any tank chemicals except a good glug of white vinegar in each empty tank.
Carol & Jeff Savournin
Usta have a '93 U225 36', Usta have a '95 U320 40', Usta have a '02 U320 40'
Usta have a 2006 Born Free, Usta have a 2011 Phoenix Cruiser
Usta have a 2012 Jeep Wrangler Unlimited 4dr
"Your time is limited, so don't waste it living someone else's life."  Steve Jobs

Re: Vacuum Toilet Protocol

Reply #5 –
On our 2003 U320, the black and grey tank both share one roof top vent (verified myself).

The black tank dump valve must be closed until dumping, or a pyramid of solids will accumulate.
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Vacuum Toilet Protocol

Reply #6 –
Geez Carol!! Now my crazy imagination sees those vacuum canisters at the bank going back and forth full of brown "stuff"!! :))
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD
 

Re: Vacuum Toilet Protocol

Reply #7 –
Quote from: AC7880 –
On our 2003 U320, the black and grey tank both share one roof top vent (verified myself).

The black tank dump valve must be closed until dumping, or a pyramid of solids will accumulate.

 See thread titled "black tank clogged".
In restless dreams I walked alone.
Narrow streets of cobblestone.


'93 U225
Build 4337
'14 CRV Toad