3 Common Types of RV Toilet Clogs You Should Know About

There are so many fun things about RVing, but toilet clogs aren’t one of them. If you keep asking yourself, “why is my toilet clogged?” or you’re wondering “how to fix a clogged toilet,” then you’re in the right place.

When your RV toilet keeps clogging, the first thing you need to do is determine which type of clog you have, because the truth is, each type of trailer toilet clog requires different methods to fix.

In this article we’re going to explain the types of RV clogs there are, how to accurately diagnose why you have a clogged toilet, and the best way to unclog an RV toilet.

Key Points About Why Your RV Toilet is Clogged

• There are three main types of clogs that can cause RV toilet blockages: pyramid plugs, compacted holding tanks, and blocked toilet lines.
• Each type of RV toilet clog needs to be approached differently, and we’ll provide the right clogged toilet fix based on your specific problem.
• Sometimes, you might think you have a clogged RV camper toilet because misreading sensors falsely indicate you have a clog, when you actually don’t.
• While your first priority is how to unclog an RV toilet, we’ll provide expert tips about how to keep your RV toilet from clogging long term.

3 Main Reasons Your RV Toilet Keeps Backing Up

If you have a clogged RV toilet, there are three main types of RV toilet clogs that you could be dealing with: pyramid plugs, compacted holding tanks, and blocked RV toilet lines. We’ll provide details about each type of camper toilet clog so that you can become more familiar with what may be happening in your RV.

1. RV Pyramid Plug

What is an RV Pyramid Plug?

RV pyramid plugs, also sometimes known as poop pyramids, develop slowly over time as waste and toilet paper accumulate in your black tank, forming into a pyramid shape right below the RV toilet line.

When this happens, the pyramid can become so large that it clogs the RV toilet pipe and prevents you from adding anything else into the black tank.

How Do RV Pyramid Plugs Happen?

The most common cause of RV pyramid plugs is when RVers leave their black tank valve open when full-hookup camping.

While it may seem logical to leave the black tank valve open to allow everything to naturally flush out, unfortunately, when you do this, all of the liquid will flow out as expected, but all of the physical waste and toilet paper tends to remain.

As the RV toilet continues to be used, the waste and toilet paper can stack on top of itself until the pyramid grows so large that it creates a clog by blocking off the pipe.

For full details about pyramid plugs, we recommend reading our guides:

• What is an RV Pyramid Plug?
• How to Get Rid of an RV Pyramid Plug?

2. Clogged RV Black Tank

What is a Clogged RV Black Water Tank?

Compacted tank clogs occur when an RV black tank has a large amount of waste that has hardened inside the tank. When this happens, solid waste blocks the exit and nothing can drain out of the tank when the black tank valve is opened.

How Do Clogged Black Tanks Happen?

The most common cause of black tank clogs is when the RV has been in long term storage with a full, or partially full, black water holding tank.

As the RV sits in storage, the liquid evaporates from the black water holding tank, leaving behind a brick of waste and toilet paper that creates the clog.

Additionally, not using a high-quality, waste-digesting RV toilet treatment or a leaky discharge valve can be other causes of clogged black water tanks.

For full details about compacted tank clogs, we recommend visiting our guide: How to Unclog a Compacted RV Black Water Holding Tank

3. Blocked RV Toilet Line

What is an RV Blocked Toilet Line?

Blocked RV toilet pipes, or clogs in black water plumbing in general, occur more quickly than other types of camper clogs. RV toilet clogs happen as waste and toilet paper move through the relatively narrow plumbing pipes and create a blockage.

How Do RV Blocked Toilet Lines Happen?

The most common cause of blocked toilet lines in RVs is flushing too much toilet paper, and not enough water down the toilet.

Blocked plumbing lines are more likely to occur when the black water tank isn’t situated directly below the toilet and the paper and poop has to travel through long lengths of pipe that may include turns and elbows in the plumbing, or because waste must travel between two black water tanks.

For full details about how to deal with RV blocked toilet lines, review our guide: How to Unclog a Blocked RV Toilet Line

Misreading Sensors & Clogged RV Toilets

Sometimes, holding tank sensors that are caked with waste, toilet paper, and debris (black water tanks), or grease and oils (gray water tanks), can misread and falsely lead you to believe your camper toilet is clogged.

Misreading sensors may tell you that the black water tank is full, but then nothing comes out when you open the black water tank valve. This could signal that you have a compacted tank, but it could also mean that you simply have an empty tank with sensors falsely reading that the tank is full. In some situations, it is even possible that you’re dealing with a clogged RV toilet and misreading sensors at the same time.

Fortunately, resolving these issues is relatively easy. For help with misreading sensors, refer to our guide: How to Clean and Restore RV Holding Tank Sensors

What to Do if Your RV Toilet is Clogged

If your RV camper toilet is clogged, try not to stress! Most clogs in RV toilets can be solved with a few simple steps. Next, we’ll take a look at how to deal with your RV clogged toilet.

Step 1: Determine What’s Causing the Clog in Your RV Toilet

Now that you know the three types of camper toilet clogs you may be dealing with, we are going to help you determine which type of clog you actually have.

It’s very important to know what type of clog there is, because you need to use a different method to fix each type.

How to Diagnose Why Your Camper Toilet is Clogged

Before trying to diagnose your RV toilet clog, 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.

Now let’s dive in and figure out what type of RV toilet clog you have:

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.
   • Does the water easily flow into the black water tank? If the answer is yes, you may have a compacted tank or misreading sensors.
2. Turn off all water sources to the RV.
3. Connect the sewer hose to the discharge port of your RV.
4. 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.
5. Shine your flashlight down the toilet for additional information.
   • 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.
   • 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.
6. Turn the water sources to the RV back on.

Step 2: Unclog Your RV Toilet

Now that you know the type of clog you’re dealing with, follow the instructions below to unclog your RV toilet.

How to Get Rid of an RV Pyramid Plug

1. Turn off your RV’s fresh water supply.
2. Using a flashlight to look into the toilet, check to see if the clog is completely blocking the 3 inch pipe that connects the RV’s toilet to the black water tank.
   • If the pipe IS completely blocked, proceed to step 3.
   • If the pipe IS NOT completely blocked, proceed to step 4.
3. Take a section of ½” PEX pipe, or a toilet snake, and run it down the toilet to create holes in the top of the pyramid.
   • Create as many holes in the poop pyramid as possible so that you will be able to fill the tank with the maximum amount of water and treatment, allowing them to begin breaking down the clog.
   • If you have an on-board black water tank rinsing system, you can also use it to add additional water to the black water tank (after poking holes in the waste), allowing the treatment to break down the pyramid more effectively.
4. Pour one entire bottle of Clear-It into the toilet bowl, and hold down the flush pedal so the product makes its way into the clog.
   • The goal here is to allow as much water and treatment to get to the clog as possible so that the clearing process can begin. The more you can fill the tank with water, the better.
5. Let the product sit in the black water tank for as long as possible.
   • Make sure to let the Clear-It work for at least 48 - 72 hours before dumping the tank.
   • Depending on the size of the pyramid plug, it could take several days for the treatment to fully break down the pyramid. Clear-It will not damage tank components, so feel free to let it sit in the tank for days or weeks!
   • If the pyramid plug still looks large when you check on it after 72 hours, try poking more holes into it and adding more water to the black water tank.
6. After at least 72 hours, or longer, dump your black water tank and confirm the clog has been removed, and water is now able to flow through your tank.
7. Rinse your tank well to ensure all of the waste and toilet paper is broken up and out of the tank. Do this by filling your black tank, then dumping. Do this twice.
   • As you break down and rinse out the pyramid plug, it is sometimes possible for waste that has broken free to create a secondary blockage. If this occurs, you’ll need to restart the cleaning process and repeat steps 4-7 again.
8. Once you’ve cleared the clog and rinsed your tank, close your black water tank valve.
9. Turn your RV’s fresh water valve back on.

Important Note: When you are completely finished with the process, be sure to close your black water tank valve, and keep it closed unless you are actively dumping a full tank. Please refer to our guide about Why It’s Crucial to Keep Your RV Black Water Tank Valve Closed.

How to Fix a Clogged RV Black Water Tank

If you’re dealing with a compacted RV black water tank, let’s unclog it with some easy-to-follow instructions.

1. Close your black water tank valve.
2. Fill your black water tank with as much water as possible.
3. Pour one entire bottle of Unique Clear-It down the toilet and into the black water tank.
4. Let the full tank of water and Clear-It sit for at least 72 hours, or longer.
   • We always recommend letting Clear-It work for at least 72 hours, but for more severe clogs, you may need to let the treatment sit for much longer.
   • Stubborn clogs may need Clear-It to work for several days beyond the initial 72 hours to fully break down the clog. There is no amount of time that is too long to let the treatment sit as it will not damage tank components in any way, in fact, the longer, the better!
5. Open the black water tank valve and dump the tank.
   • If nothing comes out, close the black water tank valve again and let Clear-It work for longer. Again, the more time you give Clear-It to work, the more successful the treatment will be.
   • For really severe clogs, you may need to use a PEX pipe to manually break up some of the waste to loosen it and allow the rest to flow out.
   • If liquid comes out, dump the black water tank.
6. Close your black water tank valve.
7. Rinse your tank well to ensure all of the waste and toilet paper is broken up and out of the tank. Do this by filling your black tank, then dumping. Do this twice.
8. Once you’ve cleared the blockage, close your black water tank valve.
   • Make sure to keep your black water tank valve closed unless you are actively dumping your tank.

Important Note: While the process to clear a compacted black water tank is simple, it does take time for the treatment to work. If time is an issue, then hiring a tank cleaning service can dramatically reduce the time it takes to clear a clogged black water tank.

These services use specialized cleaning tools to do the job in a few hours, rather than in several days or weeks. However, the tradeoff is the price – companies can often charge upwards of $500 for this type of service.

How to Unclog a Camper Toilet

If you have a blocked toilet line, the good news is that clearing this type of clog may be as easy as using a toilet plunger, in the same way that you would at home. Even if the plunger doesn’t work, the process for clearing a blocked RV toilet is very simple.

1. Turn off the supply of fresh water to your RV.
2. Hold down the flush pedal.
3. Use a toilet plunger to attempt to force the blockage out of the toilet line, similar to how you would at home. We like this plunger.
   • If the plunger clears the blockage, proceed to step 8.
   • If the plunger doesn’t clear the blockage, proceed to step 4.
4. Hold down the flush pedal and pour one entire bottle of Unique Clear-It into the toilet bowl.
5. Let the treatment sit in the toilet overnight, or longer.
   • Some clogs may be broken up in as little as a few hours, but for the majority of clogs, you can expect Clear-It to unclog your tank in 12-48 hours.
   • Stubborn clogs may require 72 hours or more. There is no amount of time that is too long to let the treatment sit, the longer the better!
6. Try to plunge the toilet again in the morning.
   • If the clog is cleared, proceed to step 8.
   • If the clog is not cleared, proceed to step 7.
7. Using ½” PEX pipe, or a toilet snake, try to break up the clog: push it down the line until it breaks through to the black water tank.
8. Once the blockage is cleared, turn the fresh water supply back on: hold down the flush pedal for a while to make sure residual residue and debris are cleared from the pipe.
9. Dump the black water tank.
10. Thoroughly rinse the black water tank: fill it completely with water and then dump the tank.

Step 3: How to Prevent Clogs in Your RV Toilet

The best way to prevent clogged RV toilets and wastewater issues is with The Unique Method.

Developed over 30 years of professional RV wastewater treatment experience, The Unique Method is designed to provide RVers with problem-free holding tanks. While no solution works like magic, following the simple methods outlined in The Unique Method allow you to break down waste, eliminate odors, and prevent sensor probe problems, simultaneously.

For more information about how to prevent RV toilet clogs in the future, we recommend reading our guide about How to Prevent Clogs in Your RV Black Water Holding Tanks.

Reviewing the Most Common RV Toilet Clogs

Dealing with a clogged RV toilet can be a huge pain, but we hope this guide helps you understand the three main types of RV toilet clogs – pyramid plugs, compacted tanks, and blocked toilet lines – and how to determine what type of clog you’re dealing with.

Accurately diagnosing your clog will help you use the correct method to resolve the problem, and get you back to enjoying life on the road.

If you’ve followed the entire process above and are still experiencing issues with a clogged RV toilet and black tank, don’t hesitate to reach out.

Our expert Customer Support Team is ready to help you fix problems and get your tanks back on track.