RV Toilet Keeps Running: What You Should Do?

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If you have an RV toilet that keeps running, it can be a source of great frustration. At every travel break, you can see your precious freshwater tank level slowly decrease as it empties into the black tank.

The good news is that it’s often a simple issue to repair. By the end of this article, you’ll know why your RV’s toilet keeps running, how to fix it yourself, and what to do if it happens again.

What Happens If Your RV Toilet Keeps Running? 

What Happens If Your RV Toilet Keeps Running

It is essential to understand what happens if your RV toilet keeps running to maintain the sanitation and safety of your RV. 

Continuous running water can lead to bacteria growth, wasted water, and costly repairs. Identifying and stopping this issue is critical in preventing further damage or inconvenience.

One way to identify a running toilet is to check the water level. If the water in the bowl remains at the same level despite flushing or not using it, the toilet is still running.

If you hear continuous dripping or running of liquid from your RV’s plumbing system, this could be another sign that your RV toilet keeps running.

Can I Stop My RV Toilet from Continuously Running? 

Can I Stop My RV Toilet from Continuously Running

Yes, it is possible to stop your RV toilet from continuously running. However, to do so, you need to identify and address the underlying cause of the issue. 

A running toilet can be anything from a leaky valve or a faulty seal to an obstruction in the plumbing system.

Remember that RV toilets operate differently than standard residential toilets when troubleshooting this issue. 

The good news is that there are common causes for a running toilet and easy steps you can take to repair it yourself.

RVBlogger Tip On Repairing RV Toilets: Check your toilet’s owner’s manual or the manufacturer sticker to find the exact model number you have in your RV before starting any repair. Doing this before things get messy will pay off if you need to order replacement parts. Also, don’t forget to write it down.

The 5 Most Common Causes of a Constantly Running RV Toilet and How to Fix Them

Most Common Causes of a Constantly Running RV Toilet and How to Fix Them

Here are seven of the most common causes of a constantly running RV toilet and how to fix them.

1. Broken RV Toilet Foot Pedal 

Broken RV Toilet Foot Pedal

The Problem: 

A foot pedal on an RV toilet that doesn’t fully close the flush ball seal can be a significant issue. This is often the cause of a constantly running toilet. 

The foot pedal is essential for flushing the toilet. It leaves the black tank pipe slightly open to allow odors to come through. If the foot pedal doesn’t fully spring back into position, the rinsing water continues to run.

Most of the time, there are a few problems that happen: Either the spring inside the foot pedal broke, the foot pedal stem that keeps the pedal in place cracks off, or the pieces that connect it to the spring snapped off.

How to Fix It: 

Don’t order any parts until you know exactly which ones you’ll need. While this seems like a common sense concept, this author learned “the hard way,” why it’s a good idea to mention this now.

  • Turn off your water supply.
  • Remove the screws from the foot pedal.
  • Examine the foot pedal and spring for any damage.
  • Replace or repair any damaged parts before re-installing the pedal.
  • Turn the water supply back on before testing the flush.

2. Fix RV Toilet Seals 

Fix RV Toilet Seals

The Problem: 

RV toilets use rubber composite and plastic gaskets for seals between parts. That includes where the floor meets the commode. Unfortunately, after years of usage and RV storage, they break down.

Proper RV toilet seal maintenance with rubber conditioners can elongate their lifespan if the manufacturer recommends it. But let’s be honest, who wants to break down and reassemble their RV toilet 2-4 times a year.

Generally, these seals last years, but when they degrade, they can be a reason why your RV toilet keeps running. A big clue that it’s a seal issue may be that there’s water on the floor around the outside of the toilet.

How to Fix It: 

Grab the noseplugs, because you will need to break down the RV toilet to find the bad seal. Also, have your debit/credit card ready, because you’ll need to order a new one.

Before you go online, call RV service center parts departments near you. They may have the seal you need in stock. Sometimes paying a little extra to get the part now is worth it.

  • Turn off the water supply.
  • With your RV toilet’s owner’s manual in front of you, carefully break down the commode.
  • Inspect each rubber or plastic gasket for damage. The one with the most damage is most likely the culprit.
  • If your instincts tell you to replace other gaskets and seals, this is the right time to do it. That way, you may prevent redoing this process in the near future.
  • Locate, buy, and replace the bad seals. Then put the RV toilet back together.
    • Only add seal conditioner, Vaseline, or other products if the manufacturer recommends it. Some of these parts may not work well with these additives.

3. Broken Water Valve

Thetford’s Water Valve is behind the commode. Dometic’s is inside the foot pedal.

The Problem: 

Another possible reason your RV toilet keeps running could be the water valve. This is the device that works with your commode’s foot pedal. It cuts the water flow from the freshwater line after flushing.

RV toilet water valves are made from a sturdy plastic composite, but occasionally, they get blocked from contamination build-up or break.

The water valve is placed in different places, based on the brand of your RV toilet. Thetford usually places it behind the bowl, and Dometic’s can be found inside the foot pedal, next to the flushing mechanism.

No matter which brand you have, make sure you disconnect from the campground water hook-up and your RV’s water pump is shut off.

How to Fix It: 

  • After you know all freshwater connections are disabled, study your RV toilet’s owner’s manual to locate the water valve.
  • (Thetford or toilets that have the water valve on the back) Disconnect the RV toilet from the floor and locate the water valve.
  • (Dometic or toilets that have the water valve within the foot pedal) Remove the foot pedal and locate the water valve. It should be in front of the flushing mechanism.
  • Remove and inspect the old water valve parts.
  • Replace them with the new parts per the instructions they provide. If it comes with a water hose, make sure it’s fastened securely.
  • Put the toilet back together or back in place.

4. Fill Tube Is Too Long 

The Problem: 

If the RV toilet fill tube is too long, it may prevent the water valve from closing properly, resulting in a running toilet. This can occur if you’ve recently replumbed your waterlines.

How to Fix It: 

  • To adjust the RV toilet fill tube length, first wiggle the toilet and tighten the bolts with a wrench to ensure its level.
  • Check the water line inlet pipe and other parts to ensure they fit tight.
  • If you find that the water line is bending, you’ll want to disconnect it and trim it down a 1/8 of an inch at a time until the connection straightens out.
  • Use a 90° elbow connection between two PEX or older clear PVC pipes if necessary.

5. Leaking Pipes 

The Problem: 

An RV toilet that keeps running can be a leaking pipe issue. Unfortunately, there are two sets of pipes you need to run through. It could be the freshwater pipes that need new PEX pipe fittings. Of course, this is the “best-case scenario.”

The dreaded bad news could be that the connection to the black tank is leaking.

Many RVs are designed where the toilet feeds directly into the black tank. Most of the time, it’s a flange seal problem (the one that seals the toilet and the floor). If that’s the issue, see the instructions about seals above.

Yet, if that seal is good, check your subfloor and exterior storage bays. Specifically, those where the toilet’s sewer line runs to the black tank. If you see evidence of water, suit up and put on gloves that are approved for working with sewer systems.

How to Fix It: 

  • Turn off the water supply. 
  • Freshwater Side
    • Inspect all freshwater lines for leaks that feed into the toilet.
    • If there are leaks at the connection points, install new connection hardware.
    • Leaks within the piping require replacement. It’s best to replace the old line with the same color (most likely blue) to identify if hot or cold water runs through it.
  • Blackwater Side
    • Inspect the sewer lines that feed into the black tank for leaking. 
    • If there are leaks in the sewer line, add a few layers of Teflon Tape on the male-side pipe connection.
    • If there is a crack on the sewer pipe itself, replace it with the correct length and type of PVC tubing (There is specific PVC tubing designated for sewer lines that’s usually black in color).

Will My RV Toilet Flood If It Keeps Running? 

Will My RV Toilet Flood If It Keeps Running

If left unchecked, your RV toilet may flood the bathroom if it keeps running. For this reason, it’s crucial to identify the source of the problem and take action as quickly as possible. 

If the water cannot escape, it will accumulate and cause an overflow, leading to potentially costly damage. 

Therefore, it’s best to check your RV toilet regularly for any signs of trouble, so you can take action before an issue develops.

Should You Fix Your Own RV Toilet or Hire a Plumber? 

Should You Fix Your Own RV Toilet or Hire a Plumber

Deciding if you should fix your own RV or hire a plumber can be tricky. Home plumbers aren’t the right ones to call. Only RV technicians have the skills and certifications to perform this type of work on a motorhome or travel trailer.

If you are comfortable with plumbing and have the necessary tools and materials, you may be able to fix the issue yourself. 

However, it’s best to call a professional RV technician if you need clarification on fixing the problem. 

An RV repair specialist can identify the source of the problem and make any repairs to the highest standard without risking further damage. They can also advise and provide guidance. 

We bought a warranty from Wholesale Warranties. One of the best things this warranty offers is the ability to use a Mobile RV Technician. There is nothing worse than having to take your rig to the dealership when you are in the middle of a camping trip.

If you want to learn more about Wholesale Warranties, check out our article called Protecting Your Travels with RV Warranties.

Does a Running RV Toilet Waste Water?

A running RV toilet can easily waste water if not fixed promptly. 

For example, when the valve in the tank cannot close properly after flushing, it draws in water while the bowl tries to refill. This can lead to gallons of wasted water. 

Can a Running RV Toilet Cause Sewage Backup?  

Yes, a running RV toilet can cause sewage backup and overflow, leading to serious health risks for anyone living in the RV and costly repairs due to water damage. 

You must address any problems with your RV toilet quickly before the issue worsens and causes permanent damage.

When Is It Time to Replace Your RV Toilet? 

When your RV toilet becomes too old or constantly needs repairs, it’s usually time to replace it. 

While troubleshooting and fixing an issue can be a great way to save money in the short term, investing in a new model could save you even more money in the long run.

If you want to see our picks for the best porcelain toilets check out our article called Porcelain Toilets Make Your RV Feel Like Home (Our Top Picks).

Final Thoughts on Fixing a Continually Running Toilet

Final Thoughts on Fixing a Continually Running Toilet

In conclusion, if your RV toilet is running, it’s essential to identify and fix the underlying issue. With prompt action, you can avoid further damage and protect yourself from potentially hazardous situations. 

Whether you repair the toilet or hire an RV technician, addressing the issue will ensure your RV remains safe and functional.


Related Reading:

1. Porcelain Toilets Make Your RV Feel Like Home (Our Top Picks)

2. Is Special RV Toilet Paper Really Needed in an RV?

3. Should You Consider a Composting Toilet for Your RV?

4. Can You Use Drano in an RV?

5. Happy Camper Tank Treatment Review: Does It Really Work?


About the Author:

Mike Scarpignato is an avid RVer and outdoorsman. He travels with his wife Susan in their Class A 2021 Thor Challenger and their Class C 2008 Gulf Stream Conquest. Mike is the owner of RVBlogger.com, TravelTrailerPro.com, MotorhomeFAQs.com, the RVBlogger YouTube Channel, and the private Facebook group called RV Camping for Newbies.

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