Among the many items in your RV, there is one that is often neglected due to the messy stigma attached to it. Fixing your toilet when it fails is an important part of RV do-it-yourself (DIY). In this two-part article, I will provide some simple tips for resolving more common toilet failures.

Whether you have a ceramic or plastic toilet, the functionality and repair procedures are largely the same. This article will detail porcelain toilets, but plastic toilet repair is similar. The key toilet components are: water valve, spring cartridge, vacuum breaker, bowl, base, and seals.

The water valve is responsible for controlling the flow of water into the bowl. From time-to-time, you may find this component springs a leak or fails to function properly. Fortunately, water valves are inexpensive and relatively easy to source. Just be sure to identify your make and model of toilet. A water valve is shown at left, but yours may look different. The valve is located near the flush mechanism at the inlet water line termination point. Before removing the valve, verify whether the leak is simply coming from a loose fitting between the valve and water line. In this case, tightening the hose clamp or threaded fitting may alleviate the issue. If not, you will need to replace the water valve. The attachment method of the water valve will depend on your toilet mode but is often two bolts, as shown in the picture. You will have to disconnect the supply line hose from the valve, which may be easier after the valve is removed. Note that if your commode is a porcelain model, it will have a spring cartridge mounted behind the water valve, so be careful during disassembly. Be sure to have rags handy to clean up the residual water spill.

It is also possible to experience a water leak between the base of the toilet and the floor. This means that the leak will be black water, so it is important to address this quickly. If you face this type of leak, first check to see if the toilet is loose on the flange. Grab the toilet and wobble it back and forth to check for movement. If there is, tighten the nuts securing the toilet base to the floor (closet) flange, but do not overtighten them. The nuts can be tightened with a 7/16” wrench. Note that porcelain models have decorative rings covering the toilet base which will have to be removed.

Also check for damage to the toilet mounting surfaces, missing nuts, etc. After securing the toilet, check to see if the leak has been stopped by repeatedly flushing the toilet. If not, you will need to remove the toilet from the closet flange and replace the flange seal. Be sure to purchase a seal specifically for your toilet, and do not use the standard seal rings available for residential toilets, as they are different. The photo below shows the water valve at the lower left of the toilet, the closet flange on the floor, and the mounting bolts.

Stay tuned for the next segment where we will discuss other leaks that may occur on an RV toilet.

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.

Robert O. ~ “I have had Coach-Net for about 20 years. I’ve had to call them on 4 different issues. Unfortunately, 2 of the 4 times was this year. But each and every time they have been friendly, understanding, responsive and extremely helpful. I am what some say “a customer for life”.