Whether fixing a damaged toilet or upgrading to a model with a higher seat or a porcelain bowl, replacing an RV toilet is a relatively easy DIY task. Most RV owners can swap in a new toilet at home with the right tools and a compatible replacement toilet.
We’re here to help you make the replacement and avoid leaving your trailer at a service center for part of the camping season or paying a technician. Follow along as we discuss everything you need to know about changing a camper toilet, from required tools to measuring for a perfect fit.
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ToggleWhat You Need to Replace an RV Toilet

The first step in replacing the toilet in an RV is picking out a compatible replacement toilet. You’ll need to check a few things to ensure your new toilet goes in without issue. To start, measure your existing rough-in, which is the distance from the center of the floor flange to the wall. The new toilet needs to have a rough-in equal to this or less.
You’ll also need to ensure there is enough space forward of the flange, especially if you opted for an elongated seat. Ensure all cabinet and entry doors are operational with the new toilet’s dimensions. If needed, you can rotate the floor flange to remedy clearance issues.
With these steps complete, gather the necessary tools and materials for the RV toilet installation. Let’s review these below in more detail.
- Adjustable Wrench
- Tape Measure
- Putty Knife
- Screwdriver (hardware type varies by brand)
- Pliers
- Towels
- Gloves
- Water Supply Line Adapter*
*May not be needed for every installation, but is most likely required if the new toilet’s water inlet location differs from the old model.
Technician Tip: If compression-style fittings (e.g., Flair-It) are used, you may need to purchase a special wrench to remove them.
How To Remove RV Toilet

When you remove the camper toilet, there will no longer be an odor barrier between the black tank and the RV’s interior. So, it’s a good idea to drain and clean the black tank before starting.
You should also try to close off the bathroom and open any windows or vents to let odors escape outside and not into the RV. Once the toilet is removed, you should find a spot to set it, such as the shower pan.
Step 1: Turn off the RV water pump
Step 2: Flush the toilet to remove stored water
Step 3: Place a thick towel under the water line before disconnecting the line from the toilet base
Step 4: Remove hold down bolt caps and loosen the nuts
Step 5: Lift the toilet up from the floor flange and set aside
Step 6: Remove the old flange seal
Step 7: Remove hold-down bolts by sliding them out and away from the flange
With the RV toilet removal complete, prep the surface by removing leftover debris from the floor and cleaning the floor flange. Now is the perfect time to inspect the floor for water damage and the floor flange for cracks. You’ll also want to verify that the floor flange is a match, sitting level, and in good condition.
If there are any floor or floor flange issues, schedule an appointment with your local service center, as they must be replaced or repaired. If you are leaving the opening exposed for any period of time, cover it to prevent odors from escaping into the RV.
Install New Toilet

It’s time to install the new toilet with the old toilet removed and safely out of your working area. Follow these seven easy steps when installing a replacement RV toilet:
Step 1: Install new flange seal
Step 2: Slide new hold-down bolts into place
Step 3: Set toilet into position on floor flange
Step 4: Secure toilet with nuts and washers, finish with nut covers
Step 5: Connect the water line using the appropriate tool
Step 6: Turn on the RV water pump
Step 7: Allow the system to hold pressure, then flush the toilet to check for leaks and function
When securing the base to the floor flange, do so until the base is flush. Avoid overtightening, as this could crack the base. If the new toilet’s water inlet location differs from the old toilet, you may need an adapter to reroute or extend the line. In some cases, this may require additional PEX hose. In others, it may require a 90° adapter. Evaluate your case to determine what additional hardware you’ll need, if any.
Technician Tip: Please note that RV toilets don’t use wax rings. Instead, they use a rubber flange seal. Wax rings tend to dry out over time and become less flexible, which can lead to leaks in a continuously moving RV.
Can I Replace a Thetford Toilet with a Dometic Toilet?
Yes, in most cases, you can replace a Thetford toilet with a Dometic toilet or a Dometic toilet with a Thetford toilet, as the mounting flanges are the same. However, if the toilets are different sizes, you may encounter clearance issues with the walls or doors, so check these before replacement. Additionally, you will need a new flange seal and hold-down bolts specific to the toilet brand and model.
What Causes An RV Toilet to Rock Back and Forth?

If your RV toilet rocks back and forth or side to side while in use, it is likely due to a broken or cracked floor flange, a soft or damaged subfloor, or a lack of screws holding the flange in place.
The only way to check for all three is by removing the toilet. Some floor flanges are simply screwed into the floor, but they can also be glued, which requires special tools for removal. Replacing the floor flange is a job best left to the professionals, so contact a service center nearby if you need to replace yours.
We hope you found this guide helpful. Learning how to replace an RV toilet can save time and money, resulting in more comfortable, aromatically pleasing family vacations!
Check out some of these other great articles about RV toilets:
Comment below if you’ve replaced yours, and let us know how it went!
Author
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Conner Lund is a Technical Content Writer. He has both hands-on experience and real-world knowledge. He’s an avid outdoorsman: camping, hiking, backpacking, mountain biking, kayaking, hunting, and fishing are all things he enjoys that you could find him doing on any given weekend. He loves to travel and see new places. He does most of his exploring and camping out of his overlanding truck with a rooftop tent.
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