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How to Clear an RV Toilet Clog

I am an RV enthusiast with more than 50 years of experience owning, driving, traveling and living in recreational vehicles.

This guide will teach you what to do if your RV's plumbing system becomes clogged and how to avoid having this problem in the future.

This guide will teach you what to do if your RV's plumbing system becomes clogged and how to avoid having this problem in the future.

RV Toilet Clogged? Don't Panic.

RV toilet clogs happen often, so knowing how to clear them and keep them functioning is important. I recently came across a video on YouTube (which I have attached to this article) that shows a young and obviously inexperienced camper trying to unclog the commode in his coach. For people like me, who know about such things, this video is almost painful to watch.

Those who take the time to learn how to maintain their toilet and tank systems would never have a situation like this because proper care and cleaning make such plumbing problems impossible.

  • If you are new to RV living and travel, before you take your first trips, you need to read this article.
  • If you have already made a mess of things, read it anyhow because it may help you to fix your issue.

At the very least, it will keep you from having to deal with one like it again!

How to clear a clog from your RV's toilet!

How to clear a clog from your RV's toilet!

Signs That You Have a Toilet Problem

The first sign of a plumbing problem is a noxious and disgusting odor that permeates your motor home or camper. When you look into the toilet, you may or may not see anything that indicates a problem, but the smell is clear evidence of trouble. When you notice it, immediately go outside and open the valve to your black water tank.

If your valve is not working properly (ie is very hard to open or close) this may be the cause of your problem. If so, you will need to take your coach to a dealership to see if they can repair the problem. Some can, and some cannot. (See the attached video for more info on this.)

  • If you have a clear sewer hose adapter, you will be able to see whether anything is coming out of the tank.
  • If you do not have this tool, simply listen. If the tank is emptying, you will hear movement.
  • If you neither see nor hear anything, or hear only minimal movement, your black water tank is either completely or partially clogged.
When your whole RV starts to smell, you know you have a problem.

When your whole RV starts to smell, you know you have a problem.

You Know Your Toilet Is Clogged. Now What?

The very last thing you should do after you discover this issue is to put anything else into your commode.

You should especially avoid trying to use products such as Drano in an attempt to clear the clog because doing so can ruin your RV’s pipes and hoses.

If you have the type of configuration that allows any gray water to empty into your commode, close those valves immediately. If you don’t, what is inside of your toilet may well make its way up to and out of the toilet bowl and onto your bathroom floor and beyond. This is a mess you definitely do not want to deal with!

Make Sure You Understand What Is Happening

Once the mess is contained in your toilet and black water tank, take a minute to stop and think about what is happening. In order to open your lines, you need to understand how they work and what caused your issue. Most people immediately start trying to clear a clog from the top of the commode, but that is never where the problem is.

When you do not maintain your RV’s sewer tank correctly and regularly, or use it properly, what happens is that toilet paper and waste build up on the bottom of the tank. If they sit there too long, they can harden into a solid mass that no amount of chemical or fluids will eliminate.

There are a few things you can do to try to correct the problem, but if it has gone on long enough, you will not be able to take care of it.

What You Will Need for Clog Clearing

To do this job, you will need another person’s help along with

  • a hose that is attached to a faucet,
  • a large bucket,
  • clothing you can throw away,
  • a good pair of rubber boots,
  • a pair of rubber gloves,
  • a plumber's snake and
  • some protective eye wear.

We tried the rigid type of snakes but they couldn't bend well enough to get the job done. The Flexisnake is thin and bends easily, which makes it easier to get clogs moving.

When you have all of your equipment and clothing ready to go, you can begin working on the clog.

Proceed With Caution

Be forewarned that this clean-out method often works, but sometimes it works too well.

If that happens, the clogged material comes out, but behind it there will be a rush of waste matter that will be strong enough to keep you from immediately attaching the hose to the tank opening before someone can turn off the sewer valve. This is the main reason you need someone to help you!

How to Clear the Waste Matter From Your RV’s Tank

Here is what you should do:

  1. Put on your protective clothing and have your helper do the same.
  2. Position your helper near the black water tank valve.
  3. Place your bucket directly beneath the sewer tank opening.
  4. Open the valve.
  5. Have your helper open the sewer tank.

At this point, there may be some waste that trickles out of the tank. Let it fall into the bucket until there is no more. If there is no “trickle”, it is time to take action.

  1. Carefully take a plumber's snake and push it up until you feel it hit the clog.
  2. Work the dowel up and down slowly to see if you can get some movement.
  3. If this happens, make sure to get out of the way and let the mess exit the hose and enter the bucket.
  4. If only a small amount comes out, have your helper close the sewer tank valve and empty the bucket into a dump station or campground toilet.
  5. After this, repeat the procedure as before.

At this point, one of two things will happen:

  1. Either you will get no further movement after a few attempts, or
  2. the clog will clear and all of the tank’s contents will come rushing out.

In the first case, you will have no option but to call for professional help.

In the second,

  1. Have your helper immediately close the sewer tank valve.
  2. Attach your sewer hose to the tank and connect it to your sewer outlet.
  3. Open the tank and let the rest of the waste matter flow into the sewer.
  4. Empty your bucket and hose down the rest of the mess.

Additional Directions

If you have been able to clear the clog using the above guidelines, you still have more to do because there will still be waste in your tank.

This is the time to read The Best Way to Dump and Deep Clean Your Rv's Sewer Tank because it gives you specific directions for cleaning, sanitizing and then maintaining your bathroom’s sewer system.

If you do this, and if you use the correct chemicals and tools coupled with good use habits, you should never have a problem like this again.

What Is Proper Use?

Proper use means never putting anything into your toilet (such as sanitary napkins, thick toilet paper or paper towels) that will not biodegrade easily and instead using biodegradable toilet paper such as the type shown here.

This tissue will dissolve itself in the tank and turn to liquid if you use the proper chemicals and are careful not to "over use" it.

Most RV owners, including my husband and myself, find that this product is the best choice for helping to avoid clogs.

Proper use also means

  • keeping your tank closed unless emptying it,
  • making sure you always use plenty of water when flushing,
  • emptying the tank regularly,
  • using safe cleaning tools and liquids,
  • doing regular deep cleanings and
  • rinsing your hoses with a gray water flush after using them to empty your waste matter.

The Best Fix for Clogged RV Toilets

Depending on its severity, clearing a clog from RV's toilet can either be relatively easy or horribly difficult depending on what is in your waste water holding tank and how long it has been there.

Make things easy for yourself. Use the right materials and cleaning routines and keep clogs from happening in the first place.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: Why does my RV toilet not empty even with the black tank empty?

Answer: It's likely that you've got a clog somewhere between the toilet bowl and the tank that is keeping the contents from emptying. Use the directions in the article to try and clear it. If you can't take it to a repair shop and have them clear it.

Question: I have drained my black water tank, but I still have water backing up in my toilet bowl and won’t drain into the black water tank. If I move my RV, it will drain. I checked the black water tank vent and water flows through it freely into the black water tank. Do you have any suggestions?

Answer: It sounds like you might have a plumbing problem. My motorhome has black water plumbing that takes two 90 degree turns on the way from the toilet to the tank, so I have to be very careful with it. If you've tried the steps and chemicals in this article and are still having problems, it's time to have an RV repair pro take a look.

Question: Nothing we do to get rid of a clog in our RV toilet seems to help. We have had this problem before, and it usually has worked, but not this time, now what?

Answer: It is possible that you have a bad valve or that there is an internal plumbing problem. If you are not handy enough to deal with these issues, you'll have to take your coach to an RV repair shop that is willing to do a job like this and pay them to clear the clog for you. This may be something as simple as replacing a part or as complicated as dropping your tank, cleaning it out, finding the problem and repairing it. You have to be very careful about what you put in your RV toilet. For example, if you are using regular toilet paper, that could be your issue! You don't want to damage your toilet or your tank, so hiring a pro at this point is probably your best bet.

Question: I smell an odor coming from behind my toilet, but the black tank is clean. What do you think the problem is?

Answer: Either the toilet isn't as clean as you think it is, you have a clog, or you may have a broken plumbing pipe.

© 2015 Sondra Rochelle