RV Toilet Not Holding Water. How Do You Fix It?

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Last Updated on August 23, 2022 by acechapman

Perhaps you have noticed a foul-smelling RV toilet recently, or perhaps slow flushing. These are all signs of an RV toilet not holding water.

This problem can be solved by replacing the blade seals of your toilet. This is done by removing your toilet and separating the base and top.

What is An RV Toilet?

Toilets come in one- or two-piece versions. RV toilets or Cassette toilets have a completely new mechanism. Thus, eliminating the need to use a large tank.

The majority of RV toilets are operated by pushing a button at the bottom. The pedal opens the flap in the toilet bowl. The toilet then drains into the black water tank underneath the RV.

rv toilet not holding water

Basic Parts Of An RV Toilet

You will be able to repair any problem you have with your toilet the more you become familiar. Before we get into the main discussion let me give you a quick overview of the basic parts and their functions.

Seal and Valve

The seal and valve are located in the middle of the toilet bowl, which then holds water. This toilet acts as a barrier against the unpleasant smells that are redirected from a sewage tank to reach the RV’s main compartment. If the smell is bad, then it is safe to assume that something is wrong and fix it.

Water Module

Access to water is essential for any toilet. The water module connects to the rig’s water supply and serves this purpose. The good news is that RV toilet manufacturers recognize the importance of this mechanism and offer replacement parts to fit their specific models of toilets.

Foot Pedal

This is where RV toilets are different from residential models. Most RVs use a foot pedal instead of a traditional hand flush. Note that the functionality of a foot-pedal will differ depending on which model you have.

For some toilets, you will have to first step on the pedal and then raise the bowl to flush the water. Others may fill the bowl halfway and flush it when they are done.

Make sure to clean your seal

Make sure to clean the toilet seat seal before you replace anything. Most RV dealers and supply shops sell tools that can clean the grooves in your blade seal. A nail file is an alternative.

Turn off the RV’s water pump first. Flush any water remaining by turning off the pump or shutting it off.

Spray cleaner onto your cleaning tool. Next, use your cleaning tool to scrape out any debris and then rinse it thoroughly with the spray cleaner. Test to make sure the problem has been resolved.

How to Replace the Blade Seal

Most toilet bowls are unable to retain water due to a leaky blade seal. These are easy to replace and cost between $10-20 on Amazon.

Although RV toilets come in a variety of designs, we will share a general guideline that will work with all toilets, especially when your RV toilet is not holding enough water. This is how to replace the blade seal.

  1. Shut off the RV’s water pump. Then, make sure to flush any water remaining by turning off the pump or shutting it off.
  2. Remove your toilet. You can do this by disconnecting your water supply line at the back of the toilet. It connects to the bottom water valve. Next, take out the two nuts that hold the toilet to the black tank and floor.
  3. The top and base should be removed. Remove the two screws through the panel at the back of your toilet. You will also need to disconnect any hoses that are blocked by certain models.
  4. Take off the top. To remove the top, rotate it while pulling upwards. If there are plastic clips that hold it on, you also have to remove them.
  5. Replace the blade seal. The blade seal should be accessible immediately. You should clean the blade seal area thoroughly before fitting your new seal.
  6. You might also consider other seals. You should replace the rubber seal between the toilet and the floor while it is still in use. This process is similar to the replacement of an equivalent seal for ordinary toilets.
  7. Install your toilet. Removing a toilet is the opposite of installing it. To make sure that your toilet bowl seals properly, you should first pour water in.

How to Temporarily  Replace A Blade Seal?

A broken seal can ruin your camping trip if you’re camping in an RV. Unfortunately, you don’t have immediate access to a blade seal replacement.

You may be able to temporarily replace your personal items with petroleum jelly. Petroleum jelly might temporarily stop the leakage.

  1. Turn off the water supply to your toilet. Then, turn off the water valve or pump and flush the toilet as usual.
  2. Stop fumes from spreading. To prevent fumes from spreading throughout your home, make sure you close the doors and skylights to your bathroom. If you leave the blade seal open, then the black water tank will be exposed.
  3. Use a cotton ball, ear swab, or cotton ball to apply the jelly. This will save you the effort of rubbing your toilet and will not cause further damage to your seal.
  4. Apply the petroleum jelly to the seal. Then, place the toilet flushing and apply the petroleum jelly on the blade seal. Make sure to inspect the area where the blade sits on the seal.

This temporary procedure will not prevent replacement, however. It may be temporary and you will not be able to replace it.

The Pedal Will Not Return

Sometimes, the pedal or lever, depending on which toilet you have, doesn’t fully return to its original position. Thus, causing the water to continue draining after you have released it.

Spray some penetrating oil on the pedal to fix it. Cover it thoroughly and continue to open and close the pedal. This will allow it to sit more easily.

rv toilet not holding water

How to Replace a Toilet Valve?

You should check the pedal to make sure your toilet isn’t filling up with water. If the pedal does not work and the toilet is still emptying, it could be the water valve.

It’s not difficult to replace the entire RV toilet, but it’s easy to replace the water valve. They are easy to find and usually cost $20 to $50 to purchase. Below are the steps:

  1. Shut off your water valve or turn off the water pump. To bleed the water pressure, flush your toilet. If you have disconnected your toilet from the water supply but still run your pump, you can use a sink instead to bleed pressure.
  2. Remove your toilet. The water supply line connecting to the water valve at the bottom of your toilet is disconnected from the back of the toilet. Then, take out the two nuts that hold the toilet to the black tank and floor.
  3. Prepare for the unpleasant stench. Because the smell is intense, you might want to have some air freshener or filter masks. To block the smell, you can cover the hole with a towel.
  4. Take off the pedal. This can usually be done by hand.
  5. The water inlet hose should be removed. The water inlet hose is usually held on by a spring compression; if this is present, use needle-nose pliers instead to take it out.
  6. The water valve should be removed. You should be able to pull the water valve off without removing one screw.
  7. Reinstall is the opposite of disassembly. So, make sure that the pedal is properly connected to the water valve. Then, turn the valve to connect the pedal to the water valve.

Frequently Asked Questions

Why does my cassette toilet have low water pressure?

Low water pressure can be caused by a few things. Problems could arise from the filter inside the foot valve. If your RV toilet is not holding enough water, remove the valve and then take it apart to clean it.

A kink or a blocked hose could cause low pressure. Remove the clog from the hose. You may have to replace the hose in this instance.

What cleaner should I use with my RV toilet?

It is important to be cautious about what cleaner you use for cleaning your toilet. Many commercial cleaners include bleach, hydrogen peroxide, as well as other chemicals. These chemicals can cause damage to the rubber or plastic seals of your pipes.

The seals can be damaged by natural cleaners like vinegar and baking soda. For cleaning the toilet, gentle cleaners made from plants are best instead.

Wrapping Up

The RV toilet is an essential part of any RV. Its role in making camping enjoyable and pleasant cannot be overemphasized.

Although it might seem strange to place too much importance on a toilet’s function, think about how frustrated and unhappy you would feel if your RV toilet is not holding water.

Image Source: By SuSanA Secretariat – https://www.flickr.com/photos/gtzecosan/13359623344/

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