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 discuss exactly what pyramid plugs are, how they develop, and how to know if that’s the type of clog you are dealing with.

Key Points About RV Pyramid Plugs

• Pyramid plugs, or poop pyramids, are the most common type of RV clog, and are often caused by leaving the black tank valve open.
• Pyramid plugs occur when waste and toilet paper build up inside the black water tank to form a pyramid that eventually blocks the bottom of the toilet line (where it enters the black tank).
• Pyramid plugs and blocked RV toilet lines share some of the same symptoms, so be sure you accurately identify the type of clog before taking action.
• Getting rid of a pyramid plug can be accomplished by following our easy instructional steps.

What is an RV Pyramid Plug?

A pyramid plug is poop and toilet paper that build up and form a pyramid shape in your black water tank underneath your RV’s toilet line. The poop pyramid can grow so large that it blocks off the pipe from the RV toilet, preventing anything else from being added to the black water tank. When this happens, the toilet can back up into the RV, making it impossible to flush anything down the toilet, and make a considerable mess.

How Do RV Pyramid Plugs Develop?

Pyramid plugs generally develop slowly over time as toilet paper and waste accumulate into a pyramid shape right below the RV toilet line. This usually occurs when hook-up campers leave their black water tank valve in the open position.

Leaving black water tank valves open is a common mistake that new and experienced RVers regularly make. Why? Well, it seems logical to leave the black water tank valve open, and assume that all of the waste, toilet paper, and liquid will flush out naturally 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 relatively flat-bottomed black water tank that most RV’s have allowed the waste and toilet paper to be left behind. This 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 can grow so large that it blocks the pipe from the RV toilet to the black water tank, creating the pyramid plug.

Other Causes of RV Pyramid Plugs

While leaving the black water tank valve open is the most common reason for a pyramid plug to develop, there are several other reasons why you may be dealing with this type of camper clog.

Long-Term Storage

When leaving a camper in long-term storage, sometimes the black water 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 water tank valve was left open, particularly during the first camping trip of the season.

Always double check that your black water tank valve is in the closed position while setting up at a full-hookup campsite.

Mechanical Failures

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.

How Do You Know If You Have an RV Pyramid Plug?

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.

Here are a few quick steps to determine if you have a pyramid plug:

1. 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.

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 Remove 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.

Final Thoughts on 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.