You might have noticed a bad smell coming from your RV toilet lately, or maybe just a flush that doesn’t clean as well as it should. Either way, these are symptoms of the same thing a lack of water in the toilet bowl.

The most common solution to this problem is to replace the blade seals on your toilet. To do this, remove your toilet, separate the top and the base, and replace it.

How Does an RV Toilet Work?

Normal toilets fall into either one- or two-piece varieties. However, RV toilets work on a completely different mechanism that removes the need for a heavy tank. 

Most RV toilets work by pushing a pedal at the bottom of the toilet. This pedal causes a flap at the bottom of the toilet bowl to open. Then, the toilet empties into a black water tank under the RV.

Clean Your Seal

Before you go to the effort of replacing anything, make sure you clean the seal your toilet blade seats against. Generally, RV dealers and supply stores sell special tools to clean off the groove in your blade seal. If you do not have one of these, a nail file will work.

First, turn off your RV’s water pump or shut off the water valve. Bleed any remaining water pressure by flushing. 

Now, just take your cleaning tool and spray some cleaner on it. Then, scrape any material out of the groove and rinse it out thoroughly with your spray cleaner. Finish by testing if the problem is fixed.

How To Replace The Blade Seal

The blade seal is the most common culprit of an inability to retain water in your toilet bowl. Luckily, these are pretty cheap to replace generally being about $10 to $20 on Amazon. 

RV toilets vary in design, but we will provide a general procedure that should help with most toilets. Here is how to replace a blade seal.

  1. Turn off your RV’s water pump or shut off the water valve. Bleed any remaining water pressure by flushing.
  2. Remove your toilet. This can be done by disconnecting the water supply line from the rear of your toilet, where it connects to the bottom of the water valve. Then, remove the 2 nuts holding the toilet to the floor and black tank.
  3. Disconnect the top from the base. You will have to remove two screws accessible through a panel in the back of your toilet. Disconnect any hoses present on some models that block removal as well.
  4. Remove the top. You will need to rotate the top while pulling up to remove it. There may be plastic clips holding it on as well, if present remove them.
  5. Replace blade seal. You should have access to the blade seal now. Clean the area it mounts into thoroughly and fit your new seal in.
  6. Consider other seals. While your toilet is out, you should consider replacing the rubber seal between your toilet and the floor. This is very similar to replacing the equivalent seal on ordinary toilets.
  7. Reinstall your toilet. Installation is the reverse of removal; however, first, pour some water into your toilet bowl to make sure it seals properly. 

How To Temporarily Seal

If you are on the road camping in an RV, a busted seal could ruin a camping trip with its nasty stench. Unfortunately, you generally do not have immediate access to a replacement blade seal. 

However, you may have a temporary replacement among your personal goods. Petroleum jelly may be able to temporarily stop or slow the leak.

  1. First, turn off your toilet water. Shut off the water pump or valve and flush the toilet to bleed like the above procedure.
  2. Second, prevent fumes. Make sure the door and skylight to your bathroom are closed to avoid fumes spreading through your house. You will have the black water tank directly exposed when you hold the blade seal open.
  3. Apply the jelly to a cotton ball or ear swab. This will prevent you from having to rub your toilet, and the cotton will not further damage your seal.
  4. Rub into the seal. Hold your toilet in the flushing position and apply the petroleum jelly to the toilet’s blade seal. Be thorough, especially where the blade seats on the seal.

This procedure is only temporary and will not preclude replacement. Still, it may hold it off until you can replace it.

The Pedal Won’t Return

Sometimes the pedal, or lever depending on your toilet, does not fully return to its stop position. This can allow water to keep draining even once you release it.

To fix this, try using some penetrating lubricant and spray it into the pedal’s joint. Thoroughly cover it and then work the pedal open and closed repeatedly. This will often help it to sit from now on.

How To Replace an RV Toilet Valve

If your toilet is not filling with water, you should first check your pedal and make sure it is working. However, if the pedal works and the toilet still does not seem to be filling with water it is probably the water valve.

Replacing the whole toilet isn’t that hard, but it isn’t that hard to replace the water valve instead. These are pretty easily found and generally will cost between $20 to $50 to buy. Here is how to replace it.

  1. Turn your water pump off or shut off the water valve. Flush your toilet to bleed the water pressure. If your toilet is already disconnected from the water supply, but you still have been running your pump, run a sink to bleed pressure instead.
  2. Remove your toilet. Disconnect the water supply line from the rear of your toilet where it connects to the bottom of the water valve. Then, remove the 2 nuts holding the toilet to the floor and black tank.
  3. Be prepared for the smell. You may want to keep some air freshener and some filter masks because the smell will be intense. You can cover the hole with a towel or other cloth to block some of the scent.
  4. Remove the pedal. You can typically pull this off by hand.
  5. Remove the water inlet hose. This is often held on by a compression spring; use needle-nose pliers to remove this, if it is included.
  6. Remove the water valve. The water valve should be able to be pulled off with or without the removal of one screw. 
  7. Reinstall. Installation is the reverse of disassembly. Remember to make sure the pedal connects to the water valve properly. If necessary, twist the valve to connect it to the pedal before connecting the valve to the toilet.

Why Does My RV Toilet Have Low Water Pressure?

There are a couple of possible problems that may cause low water pressure in the toilet. The problem could be the filter in the foot valve. If this is the case, you remove the valve, take it apart, and clean it.

Low pressure could also be caused by a clogged hose or a kink in the hose. If so, remove the clog or the kink in the hose. In this case, you may need to replace the hose.

What Cleaner Should I Use with My RV Toilet?

You should be careful what cleaner you use to clean your toilet. For example, many commercial cleaners contain bleach, hydrogen peroxide, or other chemicals. These can damage the plastic or rubber seals in your plumbing.

Even some natural cleaners such as vinegar or baking soda can damage the seals. Generally, gentle plant-based cleaners are the best choice for cleaning the toilet.