Dometic 310 Toilet Leaking Between Bowl and Base (Problems)

When it comes to leaks, you will find that all types of water leak from unusual places. That is because water will find the easiest path to exit its surroundings. The same can be said for Dometic 300 toilets. You may think it is the seal but it may not be the part that is leaking.

To repair this problem, you should call Dometic and do what they say. These instructions may not solve the problem but it will help you when you eventually find the source. That source may be the screws holding the base to the bowl. They may not have been tight enough.

To learn more about this issue, just continue to read our article. It explores the topic and provides you with the best information you need on this subject. Take a few minutes to see how this content can help you solve a smelly problem with your Dometic 300.

Dometic 310 Toilet Leaking Between Bowl And Base


Most people’s first thought when they encounter this problem thinks it is the seal that is dirty or worn out. This is a possibility but it is not the only possibility. There are other parts of this toilet that can cause this problem.

Before we get to those other possibilities, check your seal to see if it needs cleaning or replacing. If so, then do one or the other fix and use your toilet again.

Another strong candidate for this problem would be the bolts or the screws that hold the toilet in place. These can become loose through road vibration or bumps. Or they may get damaged through the same sources.

When either of these situations takes place, water will leak out between the bowl and the base. What you need to do is inspect those bolts and screws to make sure they are tight and in perfect condition.

This has been a common source for this problem as more than one RV or trailer owner has asked for help with this issue. But there is more to this problem than these two sources.

One owner found that not only were his seals dirty and needed to be cleaned, but he also found that the floor seal was not installed correctly. Replacing that seal will help solve the problem but check all the other seals as well.

Another possible source would be the water level. If the water pressure is too strong or there is too much water getting into the bowl, then you may experience this water leak problem.

Check your water pressure and water levels to make sure that the source does not cause you any problems with leaks. Finally, check for a water supply line leak. If this is the problem, simply unhook the supply line and reconnect it properly using the right plumber's tape or putty.

How To Replace a Dometic 310 Toilet Seal


The seal in the bowl will be the easiest seal to fix. You can look on YouTube to find many videos on how to fix this problem part. But you really do not need to use those videos as Dometic made this seal easy to remove and re-install.

All you have to do is pull the seal out with your fingers, clean it, or throw it away whichever you prefer, and then push the new seal back in place. When the leak is at the base there are two fixes that can be done.

The first is to tighten any bolts holding the toilet to the RV or trailer floor. That is an easy fix. Another source will be the worn-out or defective floor flange seal. This takes a little more work to repair.

You have to remove the toilet to get to this seal and replace it with a new one. Then when you are putting the toilet back in place, make sure to tighten those mounting bolts. The manual only says to replace the flange seal it does not provide any instructions on how to do that.

It is also possible that the toilet got cracked somewhere. When that happens water will leak out onto your floor. The only fix for this problem will be to replace the toilet.

There is supposed to be a bowl to base seal which can wear out and leak water. The older Dometic 310s seemed to have a 2 piece seal to handle that area of the toilet. It is not the best seal type to use.

If this seal has worn out, you will have to replace the seal but try to get the better one-piece seal that replaces the older 2-piece model. Then tighten the screws holding the bowl to the base correctly.

If those screws remain loose, you will find that the toilet will leak regardless of which seal is in place.

Other Dometic 310 Toilet Problems


Leaking water is not going to be your only problem when it comes to this toilet model. Here are a few other problems you may encounter:

- Clogging- this happens when you use too much toilet paper when you go to the bathroom. It also happens when you throw other things into the toilet to flush them away.

You can use a plunger to get some of the clog but if that doesn’t do the trick, then use a plumber’s snake.

- non-stop flowing water- you may see this take place from time to time depending on how long you own your RV and toilet. When the water won’t stop flowing into the bowl, you have a broken water valve. Replacing the valve is your only repair.

- a bad odor- this can happen when the flush ball is open or closed. If it happens when it is open, then you may have a black water tank vent that is clogged. Or it just smells.

For the first problem you will have to clean the vent to get rid of the clog and for the second add some holding tank deodorizer. If the odor takes place when the flush ball is closed, you may need to add water to the bowl.

Or you may have a damaged flush ball or floor flange seal. Replace whichever one is worn out or broken.

- water will not stay in the bowl- this tells you that your flush ball is either not installed correctly, not seated right or it is damaged and needs replacing. It may also just be dirty and in need of cleaning.

The fix for the flush ball not being seated correctly have you pressing the foot pedal, then pressing the flush ball with your finger to get it back in the right spot.

- flush ball does not close completely- when this happens it means the flush ball cannot slide against the bowl. There is a lack of lubrication and you will need to apply some silicone spray or furniture polish after cleaning the flush ball.

- leaking water valve- when you see some water around your toilet, it could mean that the water supply line is not attached to the water valve correctly. In this case, you would have to disconnect the water supply line and reconnect it correctly.

Or, the water valve is damaged and it would need to be replaced. These are just some of the issues you may find with your Dometic 310. There are enough parts, like the foot pedal, that could get damaged but some of those parts are not repairable and would require a new toilet or new assembly.

The Benefits Of The Dometic 310 Toilet


These benefits may apply to all the toilets in the Dometic 300 toilet series and not just the 310 model.

1. It provides sanitation- This toilet is designed to be a sealed unit that keeps germs and bacteria down in the black water tank where they belong. It also helps prevent sewer gas from forming which can cause some health issues if not detected right away.

2. Saves water- its tankless design makes sure you use the minimal amount of water needed to flush this toilet. Plus, there is no wasted time waiting for the tank to refill before using it again.

This toilet is supposed to use around 2 gallons or less of water with each flush.

3. Saves on space- its compact design means you can have more space in your bathroom for other items. Or it gives you more space to move around so you are not banging your arms or legs against the wall.

Things To Consider When Buying a New Dometic 310 Toilet

Things To Consider-When-Buying-a-New-Dometic-310-Toilet

There are lots of good RV toilets on the market these days. But your RV may not have the bathroom space to replace your current 310 model with something bigger or from another manufacturer.

That means you need to shop for a new Dometic 310 to preserve your bathroom design. Here are some things to guide your new purchase search:

1. Shape- the Dometic 310 should come in either a round or square shape. Just pick the shape that will fit the available space.

2. Size- all Dometic 310s should be the same dimensions. This is important as you will only have so much room from the wall to place the toilet. You want the size to be the same as the previous model to spare you any hassles.

3. Construction materials- generally, the 310 is made with high-quality plastic materials. If you can get one made with ceramic that would be better and longer lasting. Plastic does not always last that long.

4. Color- the colors you have available to choose from are, white, ivory, light gray, silver, and black. You can go with the same color or brighten your bathroom experience with something a little bit different.

5. Installation- it is said that the 310 model has a few different installation options. To save you any problems and hassles of installing your new model, make sure it comes with the installation design that fits your current design.

Winterizing Your Dometic 310 Toilet


The manual has some clear instructions on how to do this task. “Non-toxic Antifreeze Winterization (recommended method)

1. Pour antifreeze into potable water tank according to instructions from antifreeze manufacturer.

2. Flush toilet several times until antifreeze has flowed completely through toilet. For toilets with hand sprayer, the hand sprayer must be turned on to assure antifreeze is cycled through the sprayer.

Drain Water from Toilet

1. Turn off water supply to toilet.

2. Remove water supply line from water valve.

3. Place a small container under water valve inlet to catch draining water

4. Press flush pedal and allow water to completely drain from water valve and vacuum breaker.

5. Leave water line disconnected until threat of freezing temperature is past”

There is one important note after these instructions.

Toilet warranty does not cover freeze-damaged water valve

The Dometic 310 and 320 series toilet warranty expressly excludes coverage for any damages to the toilet or vehicle that may occur as a result of improper winterization of the toilet. An indicator of improper winterization is freeze damage to the water valve which results in leaks.”

There is more to those instructions and you can find the above information as well as more warranty information on pages 8-9, & 11 of the manual. it is not a very long manual and it should provide more answers to your questions about this toilet and other key details.

Some Additional Words

Most of the leaking will be caused by either a worn-out or dirty seal. But that does not mean you should not check the bolts and the screws to see if they are damaged or loose.

Water will leak out of many unusual places and it may take several tries and parts replacements to finally solve the problem. Be thorough in your cleaning and make sure all bolts and screws are tight. The odor is not pleasant when the toilet begins to leak.

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