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A Look Into How to Unclog RV Toilet!

A Look Into How to Unclog RV Toilet!

Understanding RV Toilet Clogs

An RV toilet clog can come about in various ways, each with its own underlying cause. Perhaps water refuses to drain from the bowl, or worse, it backflows in an unsettling manner. Maybe the toilet appears functional, but your tank sensors think it's full when it's not. Regardless of the symptom, the root issues often come down to a few reasons including excessive toilet paper, insufficient water usage, or good old-fashioned solid waste buildup.

Diagnosing the Clog

Before we get into unclogging methods for RV toilets, it's essential to pinpoint the precise cause of your clog.

To diagnose the issue, try this simple test- close the black tank valve, flush the toilet, and observe. If water flows smoothly into the tank, you likely have a clog within the tank itself. However, if the water backs up into the bowl, the blockage resides in the line between the toilet and RV holding tank.

The Pyramid Plug

A towering monument of solid waste and toilet paper that has accumulated from the bottom of your black tank. This is often the result of leaving the tank valve open during regular use, allowing liquids to drain while solids remain. Over time, these solids form an unsightly pyramid, eventually reaching the toilet and causing a clog.

To get rid of this, you'll need a flexible tool like a water hose. First, close the tank valve and turn off the water supply. Then, open the toilet valve (either by holding the flush pedal or using a specialized tool) and gently insert your tool into the toilet. Carefully poke and prod at the pyramid's peak, aiming to create a channel for water and cleaning solutions to seep through.

Once you've broken the top, pour a generous amount of a powerful tank cleaner into the toilet bowl. Follow up with as much water as possible, allowing the cleaner ample time (at least 72 hours) to work its magic. Finally, open the tank valve and let the now-liquid waste flow freely.

Battling Blocked Lines

Sometimes, the clog isn't in the tank but rather in the line connecting the toilet to the tank. This often occurs when toilet paper accumulates at bends or elbows in the piping, creating an impassable barrier.

To clear a blocked line, start by pouring a bottle of tank cleaner down the toilet and letting it sit overnight. If that doesn't do the trick, it's time to bring out the big guns: a plunger or a flexible snake-like tool (like a PEX pipe). Gently insert the tool into the toilet, carefully maneuvering it through the twists and turns, dislodging any stubborn clogs along the way.

Plumber with toilet plunger for clogged toilet on light background

Tackling Compacted Tanks

In some cases, the issue isn't a clog, but rather a compacted mass of solid waste that has accumulated at the bottom of your tank. This can happen due to a lack of proper tank maintenance, inadequate water usage, or storing your RV without first emptying the tanks.

To liquify this hardened mess, start by closing the tank valve and filling the tank with as much water as possible. Then, pour in a powerful tank cleaner and let it sit for at least 72 hours. After this extended soak, open the valve and let the waste flow openly. If it's particularly stubborn, you may need to gently tap the discharge pipe or use a flexible tool to dislodge any remaining chunks in the clogged tank.

RV in the sunset

Restoring Misreading Sensors

Sometimes, the issue isn't a clog at all, but rather sensors that are misreading the tank's fill level. This can happen when solid waste and toilet paper coat the sensor probes, causing them to register the tank as full when it's actually empty or partially filled.


As with most things in life, an ounce of prevention is worth a pound of cure when it comes to RV toilet clogs. By following a few simple guidelines, you can significantly reduce the likelihood of encountering this unpleasant issue.

First and foremost, always keep your black tank valve closed during regular use. This prevents the formation of those pesky pyramid plugs by allowing solid waste to remain in the tank, where it can properly break down.

Secondly, use plenty of water when flushing. Aim for at least 3/4 to 1 gallon per flush, and hold the flush pedal down for a full 10 seconds to ensure a thorough rinse.

Additionally, choose your toilet paper wisely. Opt for septic-safe, rapidly dissolving varieties, and avoid thick, plush options that can contribute to clogs.

White toilet in the middle of flushing

A Word of Caution

While we've covered various DIY methods for unclogging your RV toilet, it's important to exercise caution and avoid using harsh chemicals or excessive force. Products containing hydrochloric or sulfuric acid can damage your RV's plumbing, while forceful plunging or snaking can potentially separate pipe connections.

Always prioritize safety and follow product instructions carefully. If you're ever unsure, it's better to seek professional assistance than to risk causing further damage.


Dealing with a clogged RV toilet can be a frustrating and unpleasant experience, but with the right knowledge and approach, it's a challenge that can be overcome. By understanding the various types of clogs, employing the appropriate unclogging methods, and prioritizing preventative maintenance, you can minimize the likelihood of encountering this issue and enjoy your adventures to the fullest.

Remember, a little preparation and vigilance go a long way in keeping your RV's plumbing system running smoothly. And if you ever find yourself in need of assistance, don't hesitate to reach out to the experts at Purge Ventures LLC. Their team of knowledgeable professionals is ready to help you tackle even the most stubborn clogs, ensuring your RV toilet is always ready for your next adventure.

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Frequently Asked Questions

How do you unblock a badly blocked RV toilet system?

To unblock a badly blocked RV toilet, start by adding a generous amount of hot water to the toilet bowl to help dissolve the blockage. Use a flexible toilet snake or auger to break up and push through the clog. Let it sit for a few hours or overnight if necessary. If the blockage persists, add a specialized RV toilet chemical that helps break down waste and paper.

What is the best tool to unclog an RV toilet?

The best tool to unclog an RV toilet is a flexible toilet snake or auger. This tool is designed to navigate the bends and curves of an RV toilet's plumbing system, allowing you to reach and break up the clog effectively without damaging the pipes.

Can you use a toilet plunger on an RV toilet?

Yes, you can use a plunger on an RV toilet, but it must be done with caution. Since RV toilets and their plumbing systems are more delicate than household ones, ensure you use a plunger with a flange designed for toilets. Use gentle pressure to avoid damaging seals or pipes of the RV septic system.

How do you unclog a black tank on an RV?

To unclog a black tank on an RV, start by ensuring the tank is at least half full of water. Add a strong RV tank cleaning chemical and let it sit for several hours to break down the waste. If the clog persists, use a flexible tank wand to agitate and help dislodge the clog. Additionally, flushing the tank with a hose designed for RVs can help clear out stubborn blockages.

How do you avoid an RV toilet clog?

To avoid an RV toilet clog, use septic safe toilet paper. This is smartest option because RV specific toilet paper is able to dissolve which leads to a healthy system. Ensure you add sufficient water to the bowl before and after each use to help flush waste through the system. Regularly treat the black water holding tank with RV toilet chemicals to break down waste and prevent buildup. Avoid flushing non-degradable items, such as wipes or feminine hygiene products, which can cause blockages.


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