This Is Why Your RV Toilet Vacuum Breaker Is Leaking (Solved!)


An RV toilet breaker, or vacuum breaker, is responsible for preventing contaminated water from going into the rest of your water supply or leaking elsewhere.

To do its job, this breaker often includes a plastic disc. The water supply pressure presses the plastic disc forward so that it can cover small vent holes.

Whenever the supply pressure drops, the disc opens the vent holes again, letting in outside air and preventing water backflow.

If your RV toilet breaker is broken, the leaking disc will likely not function as it should, leading to contamination and a puddle on your bathroom floor. Luckily, fixing the issue is relatively easy.

Read on to learn the signs for spotting a broken toilet breaker, why these parts break, and what you can do about it.

Signs Your RV Toilet Breaker is Leaking

So, you walked into your RV bathroom and found that your toilet is leaking. After picking up as much free-standing water as you can, you need to pinpoint the exact cause for the leakage.

There are multiple places the toilet can be leaking from, and the toilet breaker is just one of them.

You will know that your toilet breaker is responsible if the excess water is coming from the upper part of your toilet.

This issue will be easy to spot because the back of the toilet should be wet as well since the water is overflowing from there.

“It is important to note that the float seal can cause the upper part of the toilet to overflow as well. As a result, you will have to determine if the leakage is coming from the float seal or the vacuum breaker.”

You should be able to tell simply by glancing into the toilet.

If the float seal is to blame, it will look cracked or damaged in some way. If this float seal looks normal, the toilet breaker is likely to blame instead.

Read also: The 7 Best Composting Toilet for RVs // How To Use?

Why RV Toilet Breaker Leak

Almost always, RV toilet breakers leak because of age and regular wear and tear. It is very unlikely that anything you or your other RV users are doing caused the damage.

This is simply because of the nature of this breaker. Because of where it is located and its job, it is very difficult to damage on your own.

This is good news because it means that you will likely not have to fix the RV toilet breaker again for a long time once addressing the current issue.

RV How To Repairing a leaking Vacuum Breaker on your RV’s toilet >> Check out the video below:

What To Do About It

Here are the steps for fixing a leaking RV toilet breaker:

1.      Check Out Your RV Toilet Model and Serial Number.

This step is not necessary for all people, but some users prefer to match all parts to the toilet’s model and serial number.

If that includes you, you will need to begin by finding the toilet’s model and serial number. This information will typically be located between the toilet bowl and the floor flange.

2.      Find The Repair Parts.

Whether you skipped the first step or wrote down your toilet’s model and serial number, the next thing you need to do is find repair parts for the faulty toilet breaker.

When you look online, you will be able to find a lot of replacement parts available.

If you do not need the breaker right away, you can order the part online. However, many people need the repair part immediately.

We would recommend going to a local RV dealer near you. This will allow you to get the part that day.

It should be noted that an RV toilet breaker is a bit of a unique part. Some workers may not know what you are looking for, but they should have the part, nonetheless.

We advise you to stay patient while workers are doing their best to find the part you are looking for.

Read also: This Is Why Your RV Toilet Has No Water Pressure (Solved!)

3.      Replace the Breaker.

Finally, the last step for repairing the faulty breaker is replacing it. Even if you are inexperienced at RV maintenance, replacing the breaker is really easy.

Most should be able to fix this issue with no problem on their own.

To begin, make sure to shut off the water supply. Many rigs have a shutoff valve that will isolate the toilet from the rest of the supply line.

This will allow you to cut off the supply to the toilet while still having water in the rest of the RV.

Once the water is shut off, loosen the hose clamps that begin at the foot pedal valve. These hoses are responsible for connecting the toilet to the water supply line.

Loosening these parts simply assures that no excess water is left.

This next replacement part will not be relevant to all. If your toilet has a sprayer, we recommend loosening it.

Not all RVs will come with this part. Skip if your RV does not have a sprayer hose. Now that all of the hoses are loosened, slip them off and pull the toilet’s vacuum breaker out.

If you are having trouble sliding the hoses off, you can remove the breaker without disconnecting the hoses.

This won’t be an issue, but there may be some excess water. We recommend having an extra towel on hand.

You will need to cut the hoses to remove them from the breaker. Use APEX/PVC cutter and cut them as closely as possible to the nipple ends on the toilet breaker.

Remove the rubber grommet holding the vacuum breaker to the toilet. To do this, just stick your finger into the grommet and pull it out.

Clean the opening of the toilet to confirm there is no calcification buildup. Now, you are ready to install the new breaker.

Whenever you are installing the new breaker, we recommend following any instructions that come with the new model.

Most instructions will be the same as what we are about to say. If our instructions differ from your instruction manual, follow your instruction manual.

“For installation, you simply need to reverse the removal process. Most vacuum breakers will come with new hoses, grommets, and the breaker themselves.”

Begin by putting the grommet back in place. Follow up by reinserting the breaker. Finally, reattach all the hoses and turn the water supply back on.

We recommend testing out the toilet to ensure that there is no leakage. Most likely, your toilet should be good as new.

Read also: This Is Why Your RV Toilet Ball Is Sticking (Solved!)

Final Thoughts

Even though few people have heard of the vacuum breaker, this part is crucial for a properly functioning toilet.

If your toilet is leaking from the top part, the vacuum breaker is likely faulty and needs to be repaired. Repairing it sooner rather than later is the best course of action.

In order to repair this part, you will need to find a part, disconnect hoses, and replace the faulty breaker with a new one.

For most people, the replacement process will be super easy and require minimal skills or tools.

If you replace the breaker and notice there is still leakage, we recommend checking the float seal again.

Once again, a damaged float seal has many of the same signs as a damaged breaker valve. Replacing the float seal is very easy as well, if not easier. We hoped this helped!

RV Repair: Dometic Toilet 385230335 Vacuum Breaker Leaking Quick Fix >> Check out the video below:

Mike Gilmour

Hi, I'm Mike, co-founder, and editor of RV and Playa. My passion is traveling (with my RV) and enjoying the day at the beach (Playa)! Well, I originally created this blog as a way to share what I've learned by experimenting with the RV lifestyle, and I want to help others develop in life through new skills and opportunities.

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