Part 1 in this series began a discussion about RV toilet repair and introduced possible solutions to two possible sources of water leaks. Part 2 will wrap up this article.

Seals

If you have a ceramic toilet, there is a set of seals separating the toilet bowl from the base. If this seal fails or gets debris stuck in it, it may result in either an external leak originating between the bowl and the base of the toilet, or else you may find that the bowl no longer holds water. This may manifest as either the water leaving the bowl immediately after the toilet is flushed, or the water draining out of the bowl over time.

If you find your toilet bowl does not hold water, the first task is to clean the flush ball. Be sure to inspect it while you are cleaning it, as it may have damage, causing the water to exit the bowl. In this case, you need to replace the ball.

After thoroughly wiping the ball, flush the toilet a few times and wait to see if the bowl holds water. If not, try tightening the band clamp holding the bowl to the base. If this does not resolve the issue, or you experience an external leak between the toilet base and bowl, you will need to replace the bowl seal. This requires loosening the band clamp holding the bowl to the base, removing the bowl, and replacing the seal. It is an easy task for anyone with simple DIY skills.

Water Does Not Properly Enter The Bowl

You may also find that water does not properly enter the bowl when you flush. This may be caused by insufficient water flow rate or a clogged screen filter at the water valve. Ensure your water flow rate is at least 2 gallons per minute (gpm). In the case of the screen filter, inspect the filter located at the inlet to the water valve. The other possible cause of this is clogged rim wash holes around the rim of the toilet. Use a toilet brush or cloth to clean under the toilet rim. If this does not alleviate the issue, you may need to replace the toilet bowl.

Leak From The Back of The Toilet

If you find water leaking from the rear of the toilet, the cause may be a worn or loose vacuum breaker. The vacuum breaker is located under the top rear of the toilet. Remove the white cap from the vacuum breaker and flush the toilet. If water escapes from the vacuum breaker, it will need to be replaced. If the breaker is loose, push it back into place.

While you are troubleshooting any of these symptoms, be sure to inspect the toilet components for cracks or other damage, as a cracked bowl or base can also result in leaks.

Cleaning The Bowl

Be sure to keep the bowl clean using your preferred bathroom or bowl cleanser. Do NOT use abrasives, caustic chemicals, or lubricants and cleaners containing alcohol or petroleum distillates to clean the porcelain bowl or components. Also, to avoid clogging, refrain from using standard household tissue. Use only single or double ply tissue specially designed for RV and marine toilets. Residential tissue contains adhesives used to bond the tissue layers together. These adhesives are hard for the low-flow toilets to break down and digest, which can result in clogs.

There are other failure modes that can occur with RV toilets, but the ones presented in this article series are the primary ones. Other failures may be alleviated based on knowledge acquired here, or refer to your owner’s manual or manufacturers website for more assistance.

About the Author: 

Steve Froese, an avid RV owner, traveler, and Coach-Net member since 2013, is the principal of “A Word to the Wise Technical Communications”, a published RV author, certified RV technician, and licensed Professional Engineer. He frequently collaborates with the “RV Doctor”, Gary Bunzer, and has worked with the RVIA/RVDA as a technical and training writer and consultant. Professionally, he works as a quality engineer and musician. Watch for more of Steve’s work in upcoming Coach-Net publications.

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