RVing is all fun and games until you experience a clogged toilet. The most common clogs that campers experience are called pyramid plugs, or poop pyramids, because of the pyramid-like shape they form inside your RV’s black water holding tank.
In this article, we’re going to explain what pyramid plugs are, how and why pyramid plugs develop, and how to determine whether a pyramid plug is what’s causing your clogged RV black tank. We’ll also cover some expert tips from RV techs about how to prevent poop pyramids with The Unique Method.
Key Points About RV Pyramid Plugs
- Pyramid plugs, or poop pyramids, are the most common type of RV toilet clog, and are often caused by leaving the black tank valve open.
- RV pyramid plugs typically occur when waste and toilet paper build up inside the black tank to form a pyramid that grows so large it eventually blocks where the bottom of the toilet line enters the black tank.
- Pyramid plugs and clogged RV toilet lines share some of the same symptoms, so it’s important to accurately identify which clog you have before taking action.
- You can prevent pyramid plugs by following the easy-to-follow steps outlined in The Unique Method, a tried-and-tested process designed to help you prevent 99% of wastewater issues before they occur.
What is an RV Pyramid Plug?
A pyramid plug occurs when poop and toilet paper build up inside your RV black tank and form a hardened, pyramid-shaped mound below your RV’s toilet line.
Sometimes, pyramid plugs can grow so large that they block off the pipe from the RV toilet, preventing anything else from being added to the black water tank. When this happens, it can make it impossible to flush anything down the toilet, cause toilet back ups into the RV, and generally make a considerable mess.
How Do RV Pyramid Plugs Develop?
Pyramid plugs generally develop over time as toilet paper and waste accumulate into a pyramid shape right below the RV toilet line
The most common reason pyramid plugs develop is when hook-up campers leave their black water tank valves open.
New and experienced RVers often make this mistake. Why?
Well, it seems logical to leave the black tank valve open, and assume that all of the waste, toilet paper, and liquid will naturally flush down the sewer hose and into the sewer port.
Unfortunately, this is not the case.
When the black water tank valve is left open, it’s true that all of the liquid flows out as expected, but the waste and toilet paper are often left behind on the relatively flat-bottomed black water tank that most RVs have. This problem can be compounded if the RV is not properly leveled at each campsite.
Over time, the waste and toilet paper bind together and can stack on top of each other to form a poop pyramid. When left unchecked, the pyramid plug can grow so large that it blocks the pipe from the RV toilet to the black tank, creating the pyramid plug.
Other Causes of RV Clogs & Pyramid Plugs
While leaving the black tank valve open is the most common reason for pyramid plugs to develop, there are several other reasons you may be experiencing this type of RV toilet clog.
Long-Term Storage & Pyramid Plugs
When leaving an RV in long-term storage, sometimes the black tank valve is intentionally left open to allow improved airflow in and out of the black water tank. Once the RV is removed from storage, it is incredibly easy to forget that the black tank valve was left open, particularly during the first camping trip of the season.
Expert Tip: Always double check that your black tank valve is in the closed position when setting up at any campsite.
Mechanical Failures & Pyramid Plugs
As new RVs continue to enter the market, more complex systems are being implemented for RV black water holding tank valves. From cable driven, remote systems to long pull valve handles, there are a growing number of components that can lead to black water tank valve failure.
The most common mechanical failure occurs when waste and toilet paper block the path of the knife valve, which prevents the black water tank valve from closing completely. This allows all the liquid to flow out, leaving waste and toilet paper behind, and ultimately results in the formation of a pyramid plug.
Expert Tip: Avoid knife valve failures in your RV by dumping when your black tank is at least two-thirds full (typically every 3-5 days based on tank size and usage), thoroughly rinsing after every dump, and lubricating the shaft valve with dry lube to prevent sticking over time.
How Do You Know If You Have an RV Pyramid Plug?
To clear black tank clogs effectively, the first step is to accurately diagnose the type of clog you have. Pyramid plugs and blocked toilet lines share the same symptoms but require different methods to fix, so it’s important to determine which type of clog you’re actually dealing with.
Important Note: Before trying to diagnose what’s causing your RV black tank to be clogged, we highly recommend being in a location with access to a sewer port, such as a full-hookup campground or dump station. This will give you the opportunity to do a more thorough diagnosis.
Here are a few quick steps to determine if a pyramid plug is clogging your black tank and RV toilet:
1. Use your senses to check your RV.
If your RV has been parked for an extended period of time and you are greeted with an overwhelming odor, it’s possible that the black tank was not dumped before being put in storage.
If the odor gets stronger as you approach the camper bathroom, it may indicate that you have a compacted tank.
2. Turn off all water sources to the RV.
3. Look down the RV toilet with a flashlight to check for buildup.
When looking down your RV toilet, check for the following:
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Do you get a puff of odor when you open the toilet ball valve?
- If the answer is yes, this may indicate that you have a compacted tank.
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Do you see the peak of a pyramid plug near the bottom of the pipe that connects the toilet to the black tank?
- If the answer is yes, you likely have a pyramid plug.
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Do you see that the pipe is completely blocked off with paper debris?
- If the answer is yes, you probably have a blocked toilet line.
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Do you see waste and toilet paper build up below the pipe but not touching it?
- If the answer is yes, you probably have a compacted tank.
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Do you see the floor of the tank?
- If the answer is yes, this may mean that you have misreading sensors.
- If you have plumbing fittings between your toilet and black tank, you may not be able to see into the black tank.
4. Move to a location where you can safely drain the black tank.
A full-hookup campsite is recommended, because there may be a line behind you at the dump station which can interrupt the rest of the process.
5. Connect the sewer hose to the discharge port of your RV.
We recommend having a clear elbow, or sight glass fitting, so you can easily see what is coming out of the black tank.
Unfortunately, not all sewer hoses come with these, and it’s important to be able to see what is exiting the tank.
6. Open your black tank valve.
If water flows out of the tank when you open your black water tank valve, then you may simply have misreading sensors.
If nothing flows out of the tank when you open the black water tank valve, you may have a compacted tank.
7. Add water to your black tank through your RV toilet bowl.
- Does the water collect in the toilet bowl when you push down the flush pedal?
- If the answer is yes, you may have a pyramid plug or blocked toilet line.
- If you’ve left your black tank valve open for any period of time, you may have a pyramid plug.
- If you never leave your black tank valve open, you may have a blocked toilet line.
- Does the water easily flow into the black water tank? If the answer is yes, you may have a compacted tank or misreading sensors.
8. Turn the water sources to the RV back on.
Once you’ve determined that you’re dealing with a pyramid plug, now we can help you resolve the problem.
For more detailed information about how to diagnose the type of RV clog you have, please review our guide: 3 Common Types of RV Toilet Clogs You Should Know About.
How to Get Rid of an RV Pyramid Plug
If you’ve confirmed that you have a pyramid plug – don’t stress – using our easy-to-follow steps and Unique Clear-It will help you cleanly and effectively get rid of your poop pyramid.
For full directions on how to clear a RV pyramid plug, please review our guide: How to Remove an RV Pyramid Plug.
How to Prevent RV Pyramid Plugs With The Unique Method
The best way to prevent RV pyramid plugs is with The Unique Method. Specifically designed with easy-to-follow steps, this process has been proven to help RVers get the most out of their camping experiences without clogs, foul odors, and misreading sensors.
Applying the right process (The Unique Method) and using the right products (High-Quality, Bacteria + Enzyme Based Products) will prevent the majority of your problems before they occur, allowing you to enjoy your RVing adventures, clog-free.
The following are key techniques that will help you prevent pyramid plugs as outlined by The Unique Method.
1. Keep Your RV Black Water Tank Valve Closed
Unless you are actively dumping your tank, you should keep your black tank valve closed.
Leaving your black water tank valve open is one of the fastest ways to develop pyramid plugs.
Important Note: You may be one of the lucky campers that has left your black water tank valve open without experiencing any issues. But after working with hundreds of RVers to address clogs, we can confidently tell you that it’s only a matter of time before your luck runs out. We strongly recommend that you change this practice while you’re still ahead.
Learn More: Why It’s Crucial to Keep Your RV Black Water Valve Closed
2. Use High-Quality, Bacteria-Based RV Black Tank Treatment
To prevent pyramid plugs that clog RV toilets and black tanks, you want to ensure all of the waste and toilet paper in your holding tanks are broken down and liquified.
The best way to achieve this is to regularly use a high-quality, bacteria+enzyme based holding tank treatment, like Unique RV Digest-It Ultra. This treatment is so effective because aerobic bacteria break down waste without leaving behind residue or byproducts, don’t harm tank components and seals, and tackle odors at the source (rather than masking them).
Learn More: Why You Should Use a High-Quality Waste Digester in Your RV
3. Use Plenty of Water in RV Black Tanks
Water is the most important thing you can add to your black water holding tank because it is crucial for preventing pyramid plugs and acts as a natural odor barrier.
Two places where you should always use plenty of water in your RV:
- Toilet Bowl: Keep a small amount of water in your toilet bowl at all times (unless driving) to prevent tank odors from escaping into your RV living space.
- Black Tank: Always hold down your flush pedal for 10 seconds every time you use your toilet. Not only does this provide a vapor barrier, but it also prevents pyramid plugs and compacted tanks by softening the waste, moving lingering debris away from the bottom of the toilet, and preventing it from clinging to the walls and floor of the tank.
Learn More: Why Using Lots of Water in Your RV Toilet and Tanks is Crucial
4. Rinse Your RV Black Tank After Every Dump
As a best practice, we recommend thoroughly rinsing your black tank after every dump.
Our preferred method of rinsing is filling your black tank completely full with clean water, and then dumping the contents. Repeat this 1 to 2 times to most effectively rinse your black tank.
The only way to be sure you’ve drained all the remaining waste out is to routinely fill and dump your tanks.
Important Note: This method is far more effective for thoroughly rinsing a tank than using internally mounted tank rinsers, tank wands, or external tank flushes. Our extensive testing of these external devices has proven that they are highly ineffective for the majority of RV wastewater systems.
Learn More: How to Rinse an RV Holding Tank
Getting to the Bottom of It: Everything You Need to Know About RV Pyramid Plugs
Pyramid plugs are very common in RV black water holding tanks, so don’t feel bad if you discover you have one. Instead, carefully confirm that the type of clog you have is a poop pyramid, and then use Clear-It and our simple steps to get rid of the clog for good.
After getting rid of your pyramid plug, always make sure you keep your black water tank valve closed when not dumping, and practice regular black water tank maintenance as outlined by The Unique Method.
These two effortless steps will prevent 99% of RV wastewater issues, and help you camp more, and worry less.
For more details about how to prevent RV Pyramid Plugs, visit our guide about Preventing Clogs in Your RV Black Water Holding Tanks.
