Informational Guide

How To Unclog An RV Toilet

Clogged RV toilets can ruin the perfect trip. Find out how to clear blockages & keep your RV’s waste system running smoothly here.

by Ian Haynes

When you’re on the road embarking on an RV adventure, the last thing you want to worry about is a clogged toilet. Unfortunately, though, it happens, and it usually happens at the most inopportune time. Clogged RV toilets can ruin the perfect trip, and at the very least, they can be a huge inconvenience.

Because the plumbing system in an RV is different from home plumbing, the process of how to unclog RV toilet will look a little bit different than what you’re used to. Find out exactly how to clear blockages and keep your RV’s waste system running smoothly in this complete guide.

Before grabbing the plunger or plumbing snake, it's best to first diagnose your problem and determine what's causing the clog in the first place. In most cases, the blockage is caused by a build-up of toilet paper and waste, usually located at the base of the black water holding tank (this is where the wastewater from your toilet goes).

When that happens, it’s called a “pyramid plug” - that’s an RVer’s lingo for when a pile of TP and human waste form a pyramid at the bottom of the black water holding tank. This can happen by leaving the tank’s valve open all the time, which means that every single time someone uses the toilet, the waste builds up on the bottom as the liquid flows out into the sewer, eventually creating a pyramid plug.

Another problem that might have you searching for answers on how to unclog an RV toilet tank is a compacted plug. This can happen when solid waste and TP clog up the discharge line that runs from the black water tank to the outside world. It could also be from laziness and not dumping the tank before putting the RV in storage.

Lastly, a clogged RV toilet could be explained by misreading sensors. This is actually very common, and sensors that are inaccurate could be explained by waste and toilet paper coating the sensor probes, which would cause the tank to read full when it actually isn’t.


Signs of a Clogged RV Toilet: Why Does My RV Toilet Keep Clogging?

The first sign of a clogged RV toilet is obvious: there is a build-up of toilet paper and waste that won’t go down when you flush. While that’s the clearest sign you could get, there are also a few more that could point to the fact that your toilet is clogged (or is about to be!):

  1. 1
    A strong odor coming from the toilet
  2. 2
    The toilet isn’t draining, won’t flush correctly, or is overflowing
  3. 3
    The water tank valve is difficult to open
  4. 4
    Nothing happens when draining the tank
  5. 5
    The valve is open, but the tank isn’t draining

There’s a number of different reasons for each of these things to happen, but as we mentioned before, the most common is the formation of a pyramid plug.

Different Ways to Unclog an RV Toilet

The good news is that there are a few different answers to the “how to unclog my RV toilet?” question. The one you choose depends on the nature of the clog, so check out your different options below:

The Boiling Water Method

One of the simplest tricks in the book on how to unclog RV toilet drain is to use boiling water. It’s always a good idea to start with this method before resorting to other plumbing tools or harsh chemicals since all it requires is a few pots of boiling water.

Just boil up some water (2-3 cups usually works) and slowly pour it down the toilet. Just make sure to open the toilet valve first so that the water can move from the toilet to the holding tank. The idea behind using boiling water to unclog your RV toilet is that it loosens up the clog and pushes it through.

Using a Tank Wand or Plumber’s Snake

If boiling water doesn’t work, you might need to resort to a flexible tank wand. This is a tool that all RV owners should have on hand, and it works by spraying a continuous stream of water down the toilet to try and clear the blockage from the tank. You'll want to choose a wand that's long and flexible enough to reach from the toilet to the black tank and one that's powerful enough to clean out tough clogs.

plumber snake

image source: loveyourrv.com

It’s also possible to use a plumber's snake in an RV bathroom, which is a good call if the clog is stuck somewhere between the toilet drain and the black water tank. Plungers sometimes work, but that’s only if the clog is near the top and not far down near the tank. For clogs that are deeper down, you’ll have to resort to another method.

Using a Septic Safe Declogger

Chemical clog removers are extremely useful in RVs; just be sure to use a de-clogger that's labeled as “Septic-Safe." This should be your last resort since RV plumbing is more sensitive to chemicals than home plumbing. One of the best options for RV toilets is the Thetford Aqua-Foam-Porcelain and Plastic Toilet Cleaner - it's safe for both plastic and toilets, and it's designed specifically with RVs in mind.

The Ice Cube Method

This last one is very similar to the boiling water method, but instead of using boiling water, you’ll use frozen water. After filling the toilet bowl ⅓ full, load up as many ice cubes as you can before flushing them down. Repeat flushing a few more times to let the ice cubes push through the clog.


How to Unclog RV Toilet Using a Holding Tank Cleaner

Sometimes you have to deal directly with the tank instead of the toilet. For how to unclog a RV toilet holding tank, it’s best to use a holding tank cleaner, and since this method is less labor-intensive than using a wand, a snake, or boiling up water, a lot of RVers prefer it.

There are 7 easy steps involved if you choose to go this route:

  1. 1
    Close your RV black tank valve.
  2. 2
    Add water to the tank.
  3. 3
    Pour cleaning product into the RV toilet.
  4. 4
    Let the cleaner sit for 12 – 27 hours.
  5. 5
    Open the tank valve to allow the waste to drain.
  6. 6
    Clean any remaining debris using the tank rinser.
  7. 7
    Close the black tank valve.

After completing these steps, it’s also a good idea to use a holding tank deodorizer to prevent bad smells from taking over your RV fun. One of our favorites is the Aqua-Kem Liquid Deodorant from Thetford.

aqua kem

How to Prevent Your RV Toilet from Clogging (Tips & Tricks)

Before you get into the mess of having to unclog your RV toilet - literally! - it’s best to try and prevent bathroom backups in the first place. Here are a few of the easiest things you can do for clog prevention:

  1. 1
    Buy septic-safe toilet paper.
  2. 2
    Reduce the amount of paper you use.
  3. 3
    Use lots of water with each flush (and make sure there’s water in the toilet before going).
  4. 4
    Add a waste digester to your black water tank to help break down waste.
  5. 5
    Keep your black water tank valve closed - This lets the solid waste mix with liquids and toilet paper so that it has an easier time exiting the tank when you do actually empty it.

People Also Ask (FAQs)

Can an RV toilet eventually unclog itself?

While a home’s toilet could eventually unclog itself over time, this is extremely unlikely with an RV toilet. Unlike the toilets in our home, an RV blockage doesn’t have anywhere else to go, so it tends to just keep building up and getting worse.

Should you poop in your RV?

It is 100% OK to go #2 in your RV. Expelling our waste into a toilet is a basic human comfort, and RVs are all about providing comfort to those who want to experience the great outdoors or the open road. Just be sure to fill the toilet bowl with water before you use it so that the waste can flow smoothly from the bowl to the holding tank.

Can you use Drano in a RV toilet?

Using Drano in an RV toilet isn’t recommended. The chemicals in Drano can harm the sensitive plumbing systems of an RV, so you should only use RV-safe cleaners specifically designed for this purpose.

Can I pour bleach down the RV toilet?

Nope, just like with Drano, bleach is too harsh for RV plumbing systems to handle. The holding tank is typically made out of plastic, and bleach can cut right through that.

Why does my RV toilet bubble when I flush?

A bubbling toilet - even a “burping” toilet - is actually very common in RVs. This happens because water enters the black tank, which means that air must be removed. The tank is enclosed, but there is a vent that’s sole purpose is to let air escape. This air can make its way to the toilet bowl and cause a bubbling effect in the water.


Conclusion

Owning an RV is a great investment, and while the bathroom situation in an RV isn't always ideal, just know that there are plenty of methods to fix and prevent toilet clogs. Whether you go with the boiling water method or choose to use a holding tank cleaner is up to you; just try your best to prevent clogs in the first place by using less toilet paper, using TP that’s septic-safe, and remembering that lots of water is key for every flush.

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.

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