RV Toilet Leaking On The Floor – How To Fix?

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Needless to say, RV toilet leaking is a nightmare for any RV enthusiast. Despite taking good care of it, you may experience leaks at the bottom of your toilet. Sometimes the reasons are unavoidable, but with the necessary skills, you can tackle this all by yourself. 

Don’t worry if this is new to you. In this article, I’ll walk you through a complete guide on why RV toilet leaks, and what you can do about it. 

So, without delay, let’s move on to the main discussion. 

Tools You Need To Repair RV Toilet Leaking Issues

Repair RV Toilet Leaking Issues

The good thing is, fixing an RV toilet problem doesn’t require you to have expensive tools. You only need tools that are common and easy to use.

Here are the lists of tools you need to fix an RV toilet leaking on the floor. I have added a few lines to each tool so you can have a better idea of why you need this particular tool. 

1. Rubber Gloves: I don’t need to tell you to use gloves when handling operations like fixing an RV toilet by yourself. Nevertheless, get a good pair of rubber gloves before you start the repair process.

2. Replacement Flange: If your RV toilet is leaking at base, there is a good chance you have a bad flange. Therefore, you probably have to change the flange with a new replacement flange. Make sure your replacement flange is correct in size with the old one.

3. Wax Seal: You will need a wax flange seal when installing a new flange at the drain pipe. Wax seal helps to make good contact with the toilet base and prevent leaking in the future. There are also rubber seals if you prefer.

4. Ratchet Wrench: At the base of the toilet there will be at least two bolts holding the toilet with the flange. Depending on the model you have you might need a wrench extension but in most cases, a regular crescent wrench is also fine to do the unscrewing task.

5. Chisel: Well, if you are replacing an old flange, it may not get off that easy due to glue or cement seal. That’s why a sharp chisel here comes in handy to break the seal without damaging the drain pipe.

6. Hammer: Chisel pounding work needs a hammer. Just get any hammer you have at your disposal and remember to use it carefully not to damage other components.

7. Putty knife: When changing the old flange, you will need to scrape off the previous wax seal so you can put a new one. Putty knife does this job pretty easily but you can still use any kind of scraper tool you like. 

8. Flashlight: Most RV toilet leaks are so small that it’s often hard to find one in the narrow fittings. Here flashlight allows you to take a good look at those places.

9. Hand Mirror: We all know in RV, toilet space is narrow. If there is a leak behind the unit, you won’t see it because it won’t be in your line of sight. So you can use a mirror to investigate.

10. Teflon tape: If you are dealing with an RV toilet water supply line leak, it’s an indication that you have bad fittings. A good wrap using Teflon tape will be very handy in this case. 

11. Old Towels: While fixing an RV toilet seal leaking issue, it’s normal to spill water on the floor. If you want your post-cleaning to be easy, put some old towels around the toilet base. In addition to that, you can also put your dirty components on the towels to keep your floor clean.

12. Garbage bag: This is an extra precaution to put your toilet unit in the garbage bag. You never know when you will have a messy situation. It’s better to be safe than sorry.

13. Cleaning Supplies: The final step of this operation is to clean thoroughly with a proper cleaning solution, scrubber, or brush. Keeping those supplies at hand will expedite the process.

Possible Causes For Rv Toilet Leaking

Honestly, there could be many reasons for toilet leaking. It’s not just that you have a bad flange, it could be loose fittings or there might be a crack on the bowl. All these are equally important when it comes to finding a leak.

Here are a few possible causes that can lead you to RV toilet leaking-

  1. Flange Issue
  2. Improper Fittings
  3. Cracked Bowl
  4. Loose Elbow Pipe
  5. Bad Foot Pedal
  6. Water Supply Leak

Let’s now discuss each cause and the corresponding solution so you can do the work yourself.

Comprehensive Rv Toilet Leaking Solution

Before you make any move on the leak repair, clear your workspace and prepare yourself with the necessary tools. Once you are ready, now closely inspect each toilet component to determine the origin of the leak.

RV toilet leaking Solution

Finding the Leak

First, check all the fittings whether it is a water supply line or toilet intake. If your toilet unit has a flush tank, do not leave any elbow pipes and fittings. Check them all while the tank is full. If there is any leak in any of these fittings you should have found by now.

In case you haven’t found any leaks on those items, let’s run the second phase of the investigation. Inspect the bowl for any visible cracks and shake the unit to feel loose fittings. Then Press the pedal flush and look closely at the base of the toilet. Try a couple more times if you can’t find the leak the first time. 

1. Flange Issue

When dealing with a flange issue, you either have a loose bolt or the flange is completely broken. Hence, the water leaking at the base. Try retightening the bolt and flushing a couple of times to see the leak has stopped. 

If you still see water leaking then you need to replace the flange. Here is a quick step-by-step guide on how to replace a bad flange.

1.1. Turn off water supply  

Turn off all the water supply from the toilet. If you have a flash tank, drain all the water into the black tank. Also, keep the toilet flap open so the remaining water goes down too. Finally, turn off your water pump if it has a connection with the foot pedal.

1.2. Dislodging pipes 

Now disconnect any water pipeline to the toilet. It could be flush intake or pedal intake. Remember the goal is to make your toilet plumbing free of water so when you remove the unit it won’t spill any water. Place some old towels around the toilet just in case.

1.3. Removing toilet 

Look for plastic caps and remove those to expose closet bolts. You may have to pry open the caps. Depending on the model, your RV toilet could have 3 caps or somewhat hidden caps. Check the instruction manual to find those caps.

Once you have removed the caps, use your best wrench to unscrew the nuts. Use the extension bar if you can’t reach the nut properly. Then wiggle the toilet a bit and lift it upward to break free from its place.

Put the toilet unit on an old towel, paper, or in a trash bag and store it in a safe place until your repair work is complete. 

1.4. Clearing old wax

After you have removed the toilet, you will see the flange with a wax seal. For rubber seal, you can just pull it out but in the case of wax seal, you need to scrape it clean before you remove the flange. Carefully scrape off the wax with your putty knife

It is a good idea to block the drain hole with a rag or paper so you don’t drop any tools or bolts. 

1.5. Removing Flange

If your previous flange installation process did not use glue or cement, you should be able to remove it easily. Otherwise, it will stick hard and you will need to use a chisel to break the flange.

Be careful when pounding the chisel with a hammer. You don’t want to damage the drain pipe. Your goal is to cut the edge of the ring so you can pull it easily.

1.6. Placing a new flange

Once you have removed the old flange, set it aside on a towel and clean the place for the new flange. Place the new flange in a way so that the closet bolts can line up perfectly with your toilet unit. 

1.7. Applying a new seal

After you have placed the new flange now it’s time to put a new seal. Either you got a rubber or wax seal; slowly put the seal on the flange. Make sure you are not blocking any part of the drain pipe. 

1.8. Reinstall the toilet

Place the toilet back carefully assuming you have done all the prior tasks properly. Now try retightening the nuts evenly. You don’t need to put too much pressure or it might damage the threads. Shake the unit with your hand to see it fits perfectly.

1.9. Connect water lines

When reconnecting the water lines, it’s a good time to clean all the water nozzles. And don’t forget to apply a fresh wrap of Teflon tape on each nozzle to prevent future leaking. Turn off water pumps or open the gate valve.

1.10. Testing

Now comes the moment of truth. If you are sure you have successfully completed all the steps, you should not have any problem onward. Press the flush pedal and carefully inspect each fitting with a flashlight for possible leaks. Do this couple of times to be absolutely sure. 

If there are no new leaks, Congratulations! You have fixed your RV toilet. Now you can take a victory poop if you want to!

2. Improper Fittings

The thing with the improper fittings is it’s kind of sneaky. If you are not sure about the exact leak location you will have a hard time fixing it. Use a flashlight and mirror to find out which nozzle or pipe is leaking.

Dislodge the nozzle and clean the sediment inside. Now apply Teflon wrap and reconnect to its place.

3. Cracked Bowl

Get close to the bowl and search for any visible crack on the bowl. If you can find a crack or hairline fracture and it is accessible from the outside use glue to seal it off. Otherwise, you have to get a new toilet unit.

4. Loose Elbow Pipe

If your water line system has an elbow pipe in it, look for damage or fracture. Change it immediately and place it again with proper sealant.

5. Bad Foot Pedal

RV toilet leaking at foot pedal is pretty common when your pedal mechanism and nozzles accumulate dust and get loose. Replace your foot pedal if you have damaged parts inside or simply reestablish the connection after cleaning. 

6. Water Supply Leak

Your water valve can also cause leaking due to rust and spill on the floor. If that’s the case you will see even your trusty Thetford RV toilet is leaking. So change the valve as soon as possible.

FAQs about RV Toilet Leaking

1. How to fix leaking RV toilet seal?

The only way to fix a leaking seal is to replace it with a new one. You can take help of a professional as it requires removing the whole unit. But if you have the tools and skills you can do it yourself within an hour. 

2. Why does my RV toilet keep running?

This is a pretty common issue when you have a bad valve or a flush pedal. The blocking mechanism is stuck, that’s why you see the RV toilet keeps filling up. Try manually moving the pedal to see if it stops otherwise simply replace the parts.

3. Why my new Dometic RV toilet leaking water?

If you have just installed the unit chances are your fittings are incorrect. Check those fittings thoroughly with a flashlight. If you can’t find any leak on the pipe fittings, check your base and make sure your unit has solid contact with the flange.  

Final Verdict

Regardless of the brand or model, the process of fixing an RV toilet leaking is all the same as above. I hope you have learned a great deal about finding a leak and fixing it. 

Eric Weldon
Eric Weldon
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