What to Do if Your RV Toilet Bubbles When You Flush

Having an RV is all fun and games until there is a gross toilet mishap. Though most RVs nowadays, come with some sort of toilet system, some of these can cause certain problems from time to time. One such problem can be bubbling. So, what do you do if your RV toilet bubbles when flushed? 

First and foremost, if you notice bubbles are forming in your RV toilet, you should start by flushing gently. Push down on the pedal, or release the handle (depending on the kind of flush you have) very slowly. This should help minimize the bubbling and prevent it from overflowing or spitting at you. Then clean your waste tanks and unclog the pipes.

Depending on why these bubbles are forming, there are different solutions to your problem. And you might get confused about how to solve the problem you are having. This article, therefore, discusses several different reasons and their solutions to solving your bubbling RV toilet problems. 

Why Are There Bubbles in your RV Toilet?

Gone are the days of stopping at gas stations and rest stops while traveling in an RV. Even the least expensive ones nowadays, come with some sort of a washroom equipped with a toilet and a sink. Home toilets have a waste system that works with the help of water pressure and have direct connections to the city’s sewage system. 

RV toilets, however, usually have some type of water tanks and waste tanks, from where water is supplied and also the waste is stored. As you may already know, you have to dispose of this waste using pipes at dump stations. 

As there is a limited supply of water, and most of the work is done by gravity, RV toilet systems use only the necessary amount of water to wash the waste down and collect it in the tank. Since this is an enclosed space, there are vents to let out the air.

If for some reason, the vent gets clogged, air can easily become trapped and that is when these air bubbles form and your toilet spits water when flushed. The air has nowhere else to go, so they travel back up the toilet instead of going out the vents. 

The air and waste may get trapped for the following reasons:

  • The waste tank is full
  • Pipes are clogged
  • The junction where the pipes meet the tank is blocked 
  • The vent itself is blocked

What to Do if Your RV Toilet Bubbles When You Flush?

If your RV toilet spits water when flushed, you should first figure out why it is happening. Remember to always wear latex gloves before touching anything, because these are waste systems and are filled with bacteria and germs. Depending on the reason, your approach should vary as such: 

The waste tank is full

This is the most common reason, and pretty easy to fix as well. Check the black tank or waste tank of your RV to see if it’s full. You should be able to notice if the bubbling occurs only when the tank is near full. If the tanks are full, new waste has nowhere else to go. So the waste goes back into the pipes and causes bubbles to form. 

If this keeps happening for too long, the waste can also overflow out of the toilet and spoil your whole RV. And that is one ugly scenario, none of us want to face. This will usually always be accompanied by a bad odor as well, as all of the waste does not collect at the tank, so the smell can spread. 

Get to your nearest dumping station and dump the components of the tank and clean it. Try not to overfill your black tanks and dump them regularly. This should solve the problem.

Pipes are clogged

Another common occurrence is that there is something stuck in the pipes. This causes similar effects to full black tanks, but in this case, the waste does not even reach the tank. It gets stuck somewhere along the pipe, wherever there is an obstacle.

If you have checked your tank, and they are not full but bubbling still occurs, then try cleaning your pipes. There are several ways to clean pipes as well. You could use boiling water or septic unclogging chemicals. These are intended to melt or destroy whatever is stuck down there and thus wash it away. 

You can also use special “cleaning wands” for RV toilets which spray down water with high pressure to unclog the pipes. And finally, if you have run out of options, you can put on your gloves and get in with your hands. This might be disgusting, but sometimes there are no other options left. 

The junction where the pipes meet the tank is blocked 

If the problem is not either of the first two scenarios, it could be that there is some kind of obstacle stuck right in the place where the pipe’s mouth meets the end of the black tank. In this case, the pipes should be clean and the tank would not be overfilled. So, it is harder to check for this, as you cannot see the bottom of the black tank. 

So, it is best to empty the tank and clean the whole tank using a cleaning agent or cleaning wants. You can also use your hands, or boiling water, or even septic cleaning chemicals. This should get rid of whatever is stuck at the junction. 

The vent itself is blocked

The black tanks or waste tanks should have a vent so that air pressure does not build up inside the enclosed system. If leaves, rocks, dirt, etc. may block off these vents and hence the air gets trapped inside and has nowhere to escape to. So, they travel back up the toilet and form bubbles. They may also cause your washroom to smell rather pungent.

Solving this is easy. The vent should have an opening near the top of your RV. Check that for any leaves or dirt and try cleaning it regularly, so that air escapes. This should fix the problem. Also, try to ensure that the waste liquids in your black tank do not touch the vent’s ending, and there is a sufficient gap. Do not leave the tanks full for too long, or overfill them. 

How to Prevent Your RV Toilet from Bubbling?

Prevention is always better than trying to fix a problem. If you are just a little bit careful in how you use your RV toilet, it should work just fine, and not spit water or cause bubbling when you flush.

Try to dump and empty your black tanks regularly, with short intervals. Try not to overfill them ever. Empty them whenever you are close to a dump station. Also, clean your tank regularly to ensure that dirt and waste do not build up in the nooks and crannies and cause clogs. 

Do not flush down anything that might clog the pipes. Things like diapers, sanitary napkins, paper towels, etc. should be disposed of properly. Use thin toilet paper. You can also use RV Black Tank Cleaning Solutions, which dissolve solid wastes when they are stored in the tanks. This should prevent any clogs from occurring. 

And finally, try to keep the vents and your entire RV clean. This way, there are lower chances of things getting stuck in the vent and causing a problem. And a clean RV would improve your overall RV experience as well


So even though some RV toilets bubble when flushed, it is usually pretty easy to solve this problem yourself, and not spend a lot of money on getting it fixed at a maintenance shop. Most of the time, it happens due to a clogged pipe or tank, etc. 

With just a few cleaning steps, your RV toilet should be good as new!

Scroll to Top