Black wash anti-siphon, anti-backflow valve ? - Page 2

WolfWhistle · 05-06-2017, 08:09 AM

When I was flushing, I noticed the "thing" kind of screaming and I wasn't sure it was flowing enough water to actually flush, so it went bye-bye; replaced with straight-thru fittings. I can see if the tank level reaches the height of the BT flush hose connection it could back flow / siphon, but the camper would be knee deep by that time.. at which time you would also have to have no pressure from the water supply... what the chances of both happening? I don't leave a hose (yes a hose for that purpose to you who are germaphobes). The other issue is, I seldom have to flush.... and surely if it didn't come with the feature, I couldn't do it. I'm sure the BFP is required by code. So, write me up, I'm a rebel and law breaker and I don't care!
WW

Sagecoachdriver · 05-06-2017, 08:42 AM

On my 2701ds, the anti siphon valve is directly inside from the outside hose connection for the black tank flush and under the bathroom vanity. I have a dedicated grey color hose that I used along with a black plastic backflow preventer and a 45-55psi pressure regulator. Reason for the regulator is that I have a sewer clean out at the end of my driveway and usually dump at home. The spigot at the front of my house is before the house pressure regulator and comes directly off the street at 115-130psi, That would blow the system and flusher. It works fine with just enough internal spray to do the job. If my motorhomes internal anti siphon goes, I will just remove it like so many others have done since I have an external one on the dedicated hose.

benagi · 06-08-2017, 12:24 AM

Our black tank sprayer is clogged. Getting ready to hit the road for a few days. Partially filled the black tank for now with a special cleaner to see if it will break up the clog while driving to our destination . Curious where the sprayer is located on my black tank of our 3171. Anyone know? Would like to upgrade it in the future and wandering if I will be able to do it or will I have to take to a shop to have it done. Thx

Sagecoachdriver · 06-08-2017, 12:52 AM

Quote:

Originally Posted by benagi

Our black tank sprayer is clogged. Getting ready to hit the road for a few days. Partially filled the black tank for now with a special cleaner to see if it will break up the clog while driving to our destination . Curious where the sprayer is located on my black tank of our 3171. Anyone know? Would like to upgrade it in the future and wandering if I will be able to do it or will I have to take to a shop to have it done. Thx

Ben, mine is visible just above my water pump and filter housing. Since the tanks drain on the driver's side just behind the rear wheels, look in the compartment just behind the rear wheels on the passenger side. The blank tank may be visible like mine and there is a black disk screwed into the tank with an elbow coming off it. I will take a photo tomorrow and post it. Are you sure the anti siphon back flow preventer isn't at fault?

richp · 06-08-2017, 06:15 AM

Hi,

I use a black hose for black water flushing -- no confusion on what to connect.

Also, I have a manual shutoff valve directly attached to the black flush inlet. This gave me an extra level of assurance there will be no backflow. It also stopped the inevitable small dribble of water from the inlet into the compartment on my 2014 Silverback when the hose was disconnected.

Suspenders and belt, I guess...

FWIW.

Rich Phillips

rjshiflet · 06-08-2017, 06:24 AM

Quote:

Originally Posted by richp

Hi,

I use a black hose for black water flushing -- no confusion on what to connect.

Also, I have a manual shutoff valve directly attached to the black flush inlet. This gave me an extra level of assurance there will be no backflow.

For my black water flushing, I purchased one of those very light-weight expandable hoses (https://www.dexterpaxton.com/product...utm_medium=cpc) but better than the ultra-cheap ones they sell in WalMart.

It doesn't take space, isn't heavy - isn't drinking-water safe, but can't be mistaken for my regular water hose. It's worked great for me.

benagi · 06-09-2017, 01:09 AM

Quote:

Originally Posted by Sagecoachdriver

Ben, mine is visible just above my water pump and filter housing. Since the tanks drain on the driver's side just behind the rear wheels, look in the compartment just behind the rear wheels on the passenger side. The blank tank may be visible like mine and there is a black disk screwed into the tank with an elbow coming off it. I will take a photo tomorrow and post it. Are you sure the anti siphon back flow preventer isn't at fault?

Positive it is not the anti siphon. Black tank flush has worked for 2 years. It finally clogged the sprayer on our last trip. I was told it was probably because we used the wrong TP this past trip. Also was told our sprayer is on top of the black tank and they would have to lower the tank a bit to get to the sprayer to remove and clean it. They also mentioned there is a better sprayer out there that has less of a
chance of getting clogged . Just curious if anyone else has changed their sprayer on a 3171 Forester or a 3170 Sunseeker.

johnbryanpeters · 06-09-2017, 07:17 PM

Quote:

Originally Posted by WolfWhistle

When I was flushing, I noticed the "thing" kind of screaming and I wasn't sure it was flowing enough water to actually flush, so it went bye-bye; replaced with straight-thru fittings. I can see if the tank level reaches the height of the BT flush hose connection it could back flow / siphon, but the camper would be knee deep by that time.. at which time you would also have to have no pressure from the water supply... what the chances of both happening? I don't leave a hose (yes a hose for that purpose to you who are germaphobes). The other issue is, I seldom have to flush.... and surely if it didn't come with the feature, I couldn't do it. I'm sure the BFP is required by code. So, write me up, I'm a rebel and law breaker and I don't care!
WW

You misunderstand how a siphon works.

Sagecoachdriver · 06-10-2017, 01:54 AM

Guess I've been lucky with my Black Tank Flush. If mine does clog, I may try attaching my dedicated hose with my black back flow preventer and attach it to my water heater at home. Maybe the hot water will loosen the clog if I let it sit a while under observation. Or fill the tank with hot warm and pour in some liquid soap and let it sit overnight. Dump it in the morning and try the black tank flush again. Nice having my own dump station at home (sewer line clean-out)!

SeaDog · 06-10-2017, 07:15 AM

Quote:

Originally Posted by Sagecoachdriver

Guess I've been lucky with my Black Tank Flush. If mine does clog, I may try attaching my dedicated hose with my black back flow preventer and attach it to my water heater at home. Maybe the hot water will loosen the clog if I let it sit a while under observation. Or fill the tank with hot warm and pour in some liquid soap and let it sit overnight. Dump it in the morning and try the black tank flush again. Nice having my own dump station at home (sewer line clean-out)!

You might give this some thought before you try it, the hose outlet on the house water heater is for draining and flushing so all the built calcium flakes will go out that hose and into your flush nozzle. Maybe filling the tank with concentrated tank clean and letting it sit for several days may be a better option JHMO

bubbles · 06-10-2017, 07:38 AM

Quote:

Originally Posted by richp

Hi,

I use a black hose for black water flushing -- no confusion on what to connect.

Also, I have a manual shutoff valve directly attached to the black flush inlet. This gave me an extra level of assurance there will be no backflow. It also stopped the inevitable small dribble of water from the inlet into the compartment on my 2014 Silverback when the hose was disconnected.

Suspenders and belt, I guess...

FWIW.

Rich Phillips

There are 2 valves in the check valve a spring loaded shut off valve on the output side (tank side) and a vacuum break check valve on the input side. The water that you get is the water remaining in the input tube side after the check valve closes. Just don't disconnect the pressure hose till all the water has drained back out; it's fresh water. Chances are your vacuum check valve doesn't close but do to the installation routing it's not important anyway. Just a thought.

Sagecoachdriver · 06-10-2017, 09:01 AM

All good points! Perhaps just filling the tank and dropping in 2 tablets and let it sit for a day or two to soften the flusher clog. I would think that frequent use would keep it clear.

richp · 06-10-2017, 11:05 AM

Hi Bubbles,

You're likely on target -- I'm just overly cautious and I had an extra inline shutoff valve in the garage.

Rich

WolfWhistle · 06-10-2017, 01:23 PM

Quote:

Originally Posted by johnbryanpeters

You misunderstand how a siphon works.

I understand it enough to know I don't need one. The dirty water level would have to be high in the black tank, high enough to be picked up at the flush hose to tank connection... and with hose connected to a "city" water source that lost its pressure and dirty water allowed to backflow into the city source. That is 2 failures that can't happen the way I do it. Do you understand?

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