360 Siphon Roof Vent- Black


360 Siphon Roof Vent New Improved Design RV HOLDING TANK ODOR PROBLEMS? Eliminate the “Cause” and don’t just continue to treat the “Symptoms”. Moving air is all around us, its a free resource that can be used as an extremely efficient tool. The 360 Siphon is designed very much the opposite of the conventional vent cap.  It’s patented design invites the wind from all directions and angles, channeling as much air as possible to its center.  Any wind will create a low pressure, pulling out fumes.  The design of the unit makes it physically impossible for high pressure or wind to enter the stack.  Even when an RV is stationary, a slight wind will enable the 360 Siphon to pull fumes from any holding tank.

  • Say goodbye to holding tank odors invading your RV living areas.
  • It operates in ANY wind condition, mobile or stationary using only outside air movement as the power source
  • There are no moving parts to wear out or require maintenance
  • Has a built in bug screen
  • It’s made of high quality Polycarbonate plastics.
  • Contains built in UV inhibitors for durability and long life.

Click here to see a list of RV Vent Cap Comparisons.


In an effort to save our customers money on shipping costs, 360 vents are shipped via Priority Mail for a flat fee of $9.75 when only 1 is ordered and $12.75 when 2 are ordered.  If more than 2 vents or 2 vents and additional products are ordered, shipping options from both USPS and UPS will be shown. 



The 360 Siphon is aerodynamically engineered, it has no wind resistance; it channels wind into its vortex where it creates a low pressure area at the exhaust port. The lid is a complex series of shapes that has taken 3 years of design and field testing. The siphon cannot fail, it’s the world’s only non-mechanical air check valve that eliminates stack down drafts and creates a low pressure area in every possible wind direction.

Technical Data

Product Dimensions-

The diameter of the top- 4.5 in.

Diameter of the bottom with beauty ring installed- 3.5 in.

Height- 3 in.

You’ll need 2.25 in. from the center of the pipe opening to any obstacle that might be in the way.  If your vent pipes are close together, you will need 5 1/8 in. from the centerline of each pipe.

Fits 1.5 inch ID pipe which is standard on most RV’s.  If you own a Tiffin RV or a newer Winnebago RV please call before ordering.  Some vent pipes have a 1.25 or 1.588 ID and those will not work with this 360 Siphon model. However we have a solution, so just give us a call.

How to Use: Install the unit and no longer be hassled with black or gray tank fumes. It’s that simple!



Click here for 360 Installation Instructions

Gen 1 360 shown in instructions, updated version coming soon


Solve the RV Odor Problem, Don’t Just Keep Treating It

A motto that I’ve lived by my whole life has been “Do it right the first time, so you never have to do it over again”. Doing anything over again is a waste of Time, Energy and Money.

I used this same logic back in 2008 when the holding tank odors in my first RV were so strong they were making me sick. I researched the problem on the Internet and first learned about the sewer gas known as Hydrogen Sulfide. Then I researched the different solutions and realized that deodorizers were not going to solve my problem. I didn’t want to make the sewer gas smell better, I needed to exhaust it out of the holding tank so that I wouldn’t be breathing it inside my RV.

When I reviewed all the vent cap, fume extractors, I realized that they all had moving parts that would eventually fail and need replacement. I continued looking until I found the perfect solution, the 360 Siphon. Yes it cost more than the others, but the advantages are more than worth it. It’s made of Polycarbonate Plastic with UV inhibitors to make it last for years, it has no moving parts that can fail, it has a very low profile to avoid damage, it eliminates the need for holding tank chemicals, and it has 3 patents to ensure it performs as claimed.

After replacing my original stack pipe vent caps with the 360 Siphon I never again had odors, I never again used chemicals, and they never needed replacement. It’s a great example of “Do it right the first time, and never do it over again”.

Sadly, not everyone wants to solve this problem, they make more money just treating the problem at your expense. Recently I spoke with a Parts & Service Manager at a large RV Dealership. I was telling him about how the 360 Siphon permanently solves the RV holding tank odor problem, and how it could save his customers a lot of inconvenience and money.

He looked around to be sure no one could hear him and he said, “Not only do we sell and install holding tank spray systems, we get a lot of repeat business steam cleaning the inside of holding tanks, and selling lots of chemicals. Why would we give up all that repeat revenue for a one-time, permanent solution. Do the math”.

Now folks, it’s your turn to “do the math”. You can permanently solve your RV odor problems with a one-time purchase of the 360 Siphon, or you can continue to be Repeat Revenue for your local RV Parts and Service Dealer. It’s your choice.

John Meyer

Since installing the siphon vent on my 2005 Holiday Rambler motorhome it has eliminated all of the sewer odors from inside the motorhome. This product is amazing. I am very pleased with it’s ease of installation and performance.

Apple Valley

I mounted 4 360 Siphons on our Dutch Star motor home and traveled 9200 miles this summer. WOW. What a difference they made. I started the trip using chemicals and stopped using them after 5000 miles. No one in the coach noticed the difference. They work.

Al S.
Felton, PA

The RV 360 Siphons are awesome! I have a seasonal site and every time I dumped my black tank I had a strong odor in the trailer. After installing them I haven’t had any odor inside the trailer. I’ve dumped the tank 6 times after installation and all with the same results. They work great!

Thank You,
Duane Miller

BRAVO, BRAVO, BRAVO. The RV in the “RV-360” stands for real value! Finally an end to those funky ODORS. Thanks for a great product.

Dave and Linda Thomas
Queensbury, NY

We are pretty new to RVing and the unpleasant odor condition was a real surprise the first time we experienced it. It would come and go unrepentantly while parked, and was a constant annoyance out on the road. Opening the window to vent the coach made it even worse.

I read about the RV 360 in the good Sam Magazine and I could immediately relate to the problem. In fact every time we went anywhere in our new coach, I was trying to invent solutions in my head. Your product was new and a little pricey, but I had no choice but to try one.

We are very pleased. We drove home from camping in high winds Sunday, perfect conditions for the embarrassing fume situation, and there was nothing. In fact it was windy the whole time we traveled and camped and we never had the slightest whiff. To me, this like the ceiling vent covers, hoses, electrical adapters, furnace exhaust screen etc., which few coaches come with, and must be purchased and installed at the dealer. We thought it almost comical that a new diesel motor home would be missing so many essential components which need to be purchased separately. I now consider your product one of those essentials.

Richard Messner
Frederick OK

I installed the RV 360 on both my black and gray tank vents, installation was easy and the results were immediate, the odor was gone in a matter of minutes and draining the tank was quicker than ever . . . SUPER PRODUCT!!!!!

Martin Loungo
Schuylerville N.Y.

Ease of installation, does its job well, simple/reliable construction, well designed to be functional yet attractive.

I wish this product had been available years ago.

Well worth the suggested price.

Highways Magazine (Good Sam Club)
New Product Evaluation Report

I purchased an RV360 in Yuma, Arizona. That was the best money I have ever spent. We had absolutely no odors in the coach while traveling. That was a first . . . Also, we noticed right off that there was no odors in the coach when we dumped the tanks. . . This is a great product and I am telling everyone about it.

Everet Keller

You can tell them that Ed Sawyer is a Happy Camper with two RV360s installed on his motor home, one each on the black water and gray water tanks. We no longer have any odor at all in our RV and we did before installing the RV360s. I also feel that there will be no problems with collapsed tanks when getting my tanks pumped with a vacuum truck. I also notice that when I drain the tank, it drains right away like I should and not glug glug like it did. The RV360 allows more air in the tank than the old vent cap.

Edward W. Sawyer

Smell disappeared within 15 minutes. This is an excellent product.

Lloyd Baker

All the smells disappeared instantly.

Eric Blundell

I wish had it in the summer.

Ron and Kay Neale

Why did it take so long to be invented?

Howard and Joyce Laidler

Cleans up the smell in a very short time.

Pat Polock

Immediate improvement.

Lloyd Allen


I’m 60 years old and living a life-long dream of living full time in an RV. Even though I really enjoy this lifestyle, I realized it was causing me a serious health problem.

On windy days, or when I towed the trailer, air was being forced down my stack pipes, increasing the pressure in my holding tanks and causing sewer gas, known as Hydrogen Sulfide, to enter my RV. This chemical odor is always unpleasant, but in higher concentrations can not only make you sick, but can actually kill you.

I experienced extreme fatigue, dizziness, headaches, disorientation, nausea, sweating, rapid heartbeat and shortness of breath. I literally felt like I was dying.

After this happened several times, I searched the Internet to learn all I could about this problem. I was surprised to learn that both the Black and Grey water holding tanks create sewer gas that must be properly vented.

I then researched all the Stack Pipe Vent Caps on the market. I read all the websites and even went to the RV stores and inspected all the available caps. Nearly all of them used moving parts that would accumulate dust and dirt and, through friction and wear, would eventually stop working or break.

The vent cap design from 360 PRODUCTS made the most sense to me, and with no moving parts I knew they would never need service or replacement. From the moment I installed them I’ve never had another problem with odor. Great product, I couldn’t be more satisfied. They’re a real life safer.

NOTE, the sewer gas coming out of the stack pipe is heavier than air and, depending on wind direction, can re-enter the RV through an open roof vent. If this happens, just close the roof vent and use the windows for ventilation.

John Meyer

Let us know what you think about Drain Master


Can I install the 360 Siphon Myself?
If you are uncomfortable with working with the roof membrane and water sealants, please see your local RV service center. If you are comfortable with the above then yes! See Installation Instructions Tab on the left of this one for details.
Does the RV-360 work when my RV is stationary?
Yes, parked or travelling, this roof top vent eliminates all fumes and gases from the holding tanks.
Do you have a video that demonstrates how the 360 Products work?
Yes, please see the Videos tab.
Why do I smell holding tank odors in my RV?
Tank fumes seep into the RV thru seals and dried out traps due to a higher air pressure inside the tank than in the RV.
Does cleaning the tank more regularly or adding more chemicals help?
Cleaning the tank won’t help because it’s purpose is to hold waste (waste is always dirty and stinky). Adding more odor masking agents will camouflage the fumes and gasses so it smells ‘perfumey’, but you are still inhaling methane, ammonia and other gases.
Why do we get odors sometimes when parked and not at others?
Due to wind direction. Conventional vent caps cannot handle turbulent wind which is caused by obstacles on the roof top. Depending on wind direction, updrafts and down drafts hitting the vent cap will be forced down the stack pushing fumes out of the tank. Odors will be drawn out of the tanks if a lower pressure exists in the RV than the tanks, this can be the result of certain RV doors or windows open in the relation of the wind direction. The solution to this is to maximize all wind available to create a lower pressure in the tank in all situations.
Why when we are on the highway, with a cab window open, we can smell odors?
This is due to the open window causing a lower pressure in the RV than in the tank. This is why it is important to have a vent cap in place that will insure a lower tank pressure.
Why does flushing while traveling smell so bad?
Again, its due to a high pressure in the tank now having no blockage at all to drift into the living space.
If I put water in the bottom of the toilet bowl will that prevent odors when we are on the road?
Very unlikely. All RV toilets have a small ½” overflow tube that connects the tank to the underside of the rim. Its has a slight design of a water trap but its usually dry. You can’t stop fumes under pressure.
I don't know which tank smells worse the gray water tank or the black?
In some cases the gray can be worse than the black, again the water traps often dry out due to vibration and heat. The soaps and grease that accumulate in a gray tank can get quite rancid.
Why after traveling does the RV smell bad.
Same old answer; lower air pressure existed in the RV than in the tanks.
Does a vent cap have to rotate to work properly for all wind directions?
Until the 360 Siphon, yes.
How does the 360 Siphon work?
Its aerodynamically engineered, it has no wind resistance; it channels wind into its vortex where it creates a low pressure at the exhaust port. The lid is a complex series of shapes that has taken 3 years of design and field testing. The siphon cannot fail, it’s the world’s only non-mechanical air check valve that eliminates stack down drafts and creates a low pressure in every possible wind direction.
Will it work when stationary?
Yes, it works even in the slightest breeze, stationary or driving.
What if there is no wind?
If there is no wind there will never be a problem, air pressure differential cannot happen, so odors will not exist.
Will the Stack Cap work on my house?
In some cases it can work extremely well. It depends on the problem you have, but if on those windy days that sewer odors are present, its almost certain the Siphon Stack Cap will work. Also works well on outhouses.
Will the Stack Cap work on a composting toilet?
Composting toilets are designed to draw off the moisture by venting out through the vent stack. Down drafts and extra moisture or rain is definitely not wanted. The Siphon stack cap does both as well as keeping out other airborne debris.
The black tank vent stack is very close to the cover for the exhaust fan. What is the outside diameter of the 360 Siphon vent cap?
The diameter of the base is 5 ½ inches. You need 2 ¾ inches from the center of the pipe opening to any obstacle that might be in the way. The top of the 360 is the same diameter as the base. The height above the rooftop is 2 ½ inches after installation.
The 360 Siphon will be very close to my vent fan, won't fumes come into the living space from the 360?
You will probably need to keep your exhaust fan vent lid closed in higher winds. Our product really does what it says and creates a constant draw on the holding tanks and may re-enter the RV through the open vent if it is.

If you notice a smell coming in the vent fan, simply close the fan.

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