Tuesday, October 3, 2023


Ask Dave: Can I move my RV’s toilet?

Dear Dave,
I want to remodel my RV’s bathroom, which would include moving the toilet. It would still be above the holding tank but I would need to put the fitting in a different location. Is there a way to install a new fitting in the tank? I would plug or cap (whichever is appropriate) the existing one. —Dave, 2000 Southwind 34N

I have changed out several toilets in RVs but never actually moved one to another location. However, having created dozens of factory tour videos for Winnebago and other RV manufacturers, I do have a pretty good idea of how it might work.

Ways to move an RV’s toilet

Thinking it through, you could cut a hole in the floor for the new location. Typically, the Southwind did not have any metal framework embedded into the floor so it could go just about anywhere.

The issue would be cutting a hole in the black holding tank and getting a flange to seal. Here are a couple photos of the flange and what you would have to deal with.

Another issue would be making sure not to get plastic shavings in the tank. You’d have to make sure you flush everything out of it or it will get in the way of the spade valve. Notice there is not only the black removable flange, but also a PVC pipe coming up from the holding tank that is secured to the tank.

The hole in the floor should be large enough for you to get a hole saw down to the tank and cut a 3” hole in the top of the tank. Then you will need to install the rubber grommet and make sure it gets the entire groove around the plastic of the hole and is sealed.

What to do with the original drain hole

You might be able to get the old one out of the tank. However, I would be more inclined to leave that one all sealed and just cap it off. You can purchase a new grommet on Amazon or etrailer.com like the one pictured. That way you don’t have an open hole in the top of the tank and need a patch, which might not stay sealed as the tank expands and contracts during use.

Once you get the grommet sealed, insert the new pipe and it will actually sit in the rubber so you can reinstall the flange. In the project featured here, we installed a taller porcelain toilet that needed a different flange. You might be able to reuse the existing one if you can get it off without breaking the plastic. I would have another one handy just in case. You never want to break something in a black water system and not have the part. No matter how clean you think the tank is, it’s not good to let it sit open to the inside air very long!

Good luck and keep us posted! Here is how our new toilet ended up.

 You might also enjoy this

Know Your RV: 7 tips for a happy RV toilet

By Russ and Tiña De Maris
For many new to the RV lifestyle, the RV toilet is a mysterious dweller in a tiny closet. But if you plan on spending any time with your RV, you’ll soon need to get intimately acquainted. Here are important tips to get along with what can be a good friend on the road. Get all the down and dirty details here.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here


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Dave Solberg
Dave Solberghttp://www.rv-seminars.com/
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


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