Last updated on July 25th, 2023 at 07:54 am
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Are you having trouble with your RV toilet? If you notice a plumbing malfunction while you are on the road, it can spell disaster for your trip, especially given that most RVs only have a single bathroom.
So, why does your RV toilet bubble when flushed? You could have a full black tank, a buildup of solids at the bottom of your tank, a clogged drain pipe, or even a blocked black tank air vent. Work through each problem one at a time to figure out the issue.
But what does all of this even mean and, more importantly, how can you fix it? Let’s take a look at some of the most common reasons why your RV toilet might be bubbling when flushed!
Why Does My RV Toilet Bubble When Flushed?
RV toilets bubble far more often than you may think- in fact, many RVers have affectionately called it “burping”! While it isn’t a very pleasant concept, there are many reasons that your RV toilet bubbles when flushed, and just as many solutions.
Reason 1: The Black Tank is Full
The most common and easiest problem to fix? Your black tank is full!
Your RV toilet burps and bubbles when it has a full black tank and, if left alone, your RV black tank waste could even back up into your toilet.
Pay attention to the amount of waste in your black tank, especially if you don’t have convenient tank monitors. Even these tank monitoring systems can malfunction, so it’s important to look inside your black tank every now and then!
Reason 2: Solid Waste Buildup In Black Tank
If you have just emptied your black tank but your RV toilet bubbles still, you may have a decent amount of solid waste buildup inside the black tank. Solid waste buildup can be anything that has been flushed down your RV toilet and isn’t dissolving or being swept away when it comes time to empty your tank.
It’s waste as well as toilet paper or other paper products (and possibly even some products that should never be flushed down an RV toilet!). Every time you flush, you have the potential for disturbing pockets of air inside your black tank. This is especially true if you have a large amount of solid waste buildup at the bottom of your black tank.
This can be difficult to see sometimes given the nature of black tanks, but take some time to investigate with a flashlight if your RV toilet bubbles for no apparent reason.
Reason 3: Blocked Drainage Pipe
If you can’t seem to find a clog in your black tank or toilet and it still burps when flushed, check on the status of your drainage pipe and sewer hose. These pipes are a part of the exterior plumbing system on your RV and are necessary parts when it comes time to empty your tanks.
Your sewer hose is unlikely to have a block, given that it is flexible and consistently being removed from your RV. However, the drainage pipes found beneath your rig could have the potential for severe blockages.
Reason 4: Clogged Black Tank Air Vent
Did you know that your black tank has an air vent? Since your black tank is otherwise closed off, it is necessary for your black tank to have an air vent to release gases and other things from your black tank.
This pipe extends up through the roof of your RV, and it is a necessary piece of your RV plumbing system. However, this air vent does indeed clog, leading to an RV toilet bubble when flushed.
How Can I Stop My RV Toilet From Bubbling When Flushed?
Now you know of a few different reasons why your RV toilet might be burping, how can you fix it? Let’s go over a few basic troubleshooting techniques now.
Empty Black Tank
Very rarely are things simple with an RV, but if your RV toilet is bubbling, perhaps it’s simply time to empty the black tank. If you notice your toilet bubbling when it’s flushed and you know your black tank is full, this could be a very easy fix for you!
Find the nearest dump station and allow your black tank to empty completely. Run a few rounds of fresh water through the tank if possible, and check to see if your RV toilet bubbles when flushed after everything is empty and clean.
If it no longer burps, you’ve fixed the problem! If it still bubbles when flushed, you may have a bit more troubleshooting to do.
Use Black Tank Treatment
If you’ve emptied your black tank but it still has solid waste buildup along the bottom of the tank, it could be time to treat your black tank with various solutions. This could include various home remedies as well as powerful chemical treatments.
I personally recommend putting a bag or two of ice into your black tank and driving around in the RV. This has been a proven quick fix for clogged black tanks, and it could help prevent your RV toilet from bubbling!
You can also purchase a proper black tank cleaner (my go-to recommendation), a powerful chemical treatment option that dissolves any and all solid waste found inside your RV. There are many different types of black tank cleaners- just take care to follow the instructions on the packaging.
You may also consider RV-safe toilet paper for future use, as these are designed to dissolve much easier than traditional toilet paper. If you have an older RV sewer system like I do, this type of toilet paper can be a lifesaver!
Snake Your Drainage Pipe
Your tank may not be clogged, but your drainage pipe might be. These pipes lead out from your black and gray water tanks along the underbelly of your RV. They end at the sewer valve, where you attach a sewer hose in order to dump your tanks. These pipes are large, but still very capable of building up waste over time, especially if you experience very hot or very cold weather in your RV.
You may need to dissolve some of the clogs found throughout these pipes. This is a bit easier said than done, given it’s impossible to see into the pipes or readily access them. Fortunately, there are a few products I recommend trying if you think a clog has developed in your sewer system.
You may consider purchasing a snake hose attachment that allows you to blast water into the sewer pipes. You may have to get a little dirty if the clog can’t be reached using the snake inside of your black tank- just make sure to always put on disposable gloves when cleaning your sewer system!
You can also purchase a sewer hose attachment that is capable of blasting water through your drainage pipes and black tank. These products are useful for removing debris in hard-to-reach places in your sewer system. The video below is a great example of a snake contraption working successfully on a toilet clog in a fifth wheel.
Make Sure Your Air Vent Is Clear
If you haven’t been up on your RV’s roof yet, it may be time if your toilet bubbles when flushing! It may seem strange, but your black tank needs an air vent, and these vents always extend up through the roof of your RV.
Your black tank air vent has the potential to clog, but not with waste from your sewer system. Leaves, mud, bugs, and other wildlife have been known to clog black tank air vents, and if you have never peered into this pipe before, now may be the time.
Use a ladder to reach your RV’s roof and bring a flashlight with you. Look into your black tank air vent and see if you can find any obstructions. You can use your snake hose attachment and clean out your air vent with water and pressure.
Take care that no wildlife is still living in your RV vent before turning on the hose. Birds have been known to nest in these vents!
How To Prevent The Dreaded RV Toilet Bubble When Flushed?
You’ve found your various clogs and have cleared them. Now your RV toilet doesn’t bubble or burp anymore when you flush. Fantastic news!
But what maintenance can you perform so this doesn’t happen again anytime soon? Let’s go over a few helpful preventative techniques.
Flush Slowly And With Lots Of Water
One of the simplest ways to prevent a buildup or clog in your RV’s sewer system is flushing with extra care. RV toilets are very different from conventional home toilets- they are reliant on you in terms of how much water is needed for flushing.
Many RV toilets operate similarly in that there’s an option to fill your toilet bowl with water before flushing. Doing this operation in a slow and steady manner, allowing the toilet bowl to fill completely, may help mitigate some of the toilet bubbles.
While water may be limited if you are boondocking in your RV, it’s important to flush your toilet with plenty of water to prevent waste buildup. This simple daily step could make a difference in your RV sewer system!
Treat Your Black Tank Frequently
These stronger chemical black tank treatments aren’t just for emergency use! As a full-time RVer, I treat my black tank monthly, so I never have harmful buildup or clogs. Plus, these chemical treatments can help mitigate the various smells coming from your black tank.
You may also wish to consider some home remedies for cleaning your black tank including vinegar and hot water solutions. If you are camping and don’t have access to a more powerful black tank treatment, there are many home remedies that could help.
Purchase A Drain Pipe Cleaner
Having a sewer hose attachment or a snake can be a great RV accessory to have, especially if your sewer system is prone to clogs. These are often inexpensive and effective solutions and are usually small enough to store with ease.
Your RV pipes can clog just as easily as your black tank, so keep this in mind when storing your RV, especially at the end of the camping season. You should ensure that your entire sewer system is clean and ready for next year!
Inspect Your Air Vent Seasonally
Given that your black tank air vent is a crucial piece of the RV sewer system, take care to inspect this pipe seasonally. While this type of clog can be rare, it is a main contributor to an RV toilet bubble, and it is a piece of RVs that is often overlooked.
Always investigate your air vent before spraying water down the pipe. Wildlife could be trapped inside, or there could be a buildup that needs to be removed in a specific way. Take your time investigating this air vent, and make note of any potential clogs or buildup.
Take Your RV To A Professional
There are many reasons why your RV toilet bubbles when flushed, including a broken toilet or various other valves found in your RV’s water and sewer systems. Sometimes problems aren’t obvious, especially in an RV!
If you have been troubleshooting this problem for some time and still haven’t found a solution, it could be time to take your rig in to see some professionals. Let them know in detail what is happening when you flush your toilet, and they should be able to diagnose the problem.
While RV professionals can be expensive as well as booked out for up to months in advance depending on your location, it’s always nice to bring your rig in for a tune-up every now and then, especially if you are struggling with your RV’s sewer system!
Can A Plunger Fix A Blocked Or Bubbling RV Toilet?
It’s normal to experience a blocked RV toilet or one that bubbles when flushed and head straight for a household plunger. This may seem a good idea at first, however, a plunger definitely isn’t the best piece of kit for an RV toilet blockage.
Typically, black water tanks and RV toilets experience issues due to a buildup of waste or a clog, and it isn’t a case of suctioning these blockages out. Instead, they need to be fully removed so the RV toilet plumbing system will function at its best once more.
Using a plunger on an RV toilet can also damage the seals. If there is a small blockage, it may be possible to use a plunger gently to remove it, but this is something to be very cautious of as damage can occur. I think it’s wiser to use RV-specific equipment and treatments to avoid any regrets!
If your RV toilet bubbles when you flush it, you’re not alone. This common problem has plagued many RVers since the beginning of RV bathrooms!
I hope that you have found some solutions in this article, and feel prepared to tackle your RV’s sewer system, no matter how unpleasant it can be sometimes. Happy travels!