What Fitting Would be Needed to Cap Off Water Line that Runs to RV Toilet

Updated 06/11/2026 | Published 06/09/2026

Question:

Hello, I am removing a toilet permanently from my rv using a composting toilet instead. I need a way to plug the water line that goes to the toilet before I can remove it. Can you help me find the correct product? I have pictures I can send if there is a way to attach them. It looks like theres an elbow attached to the line with a clamp, and that elbow fitting has a female threaded end. So I either need a clamp just like the elbow fitting thats just a plug, or a male threaded plug that fits the female threaded end on the elbow. I see you have a 1/2 male threaded plug, but this looks more like 3/4. Its hard to tell the exact measurement. Thanks, Stephanie

asked by: Stephanie M

Expert Reply:

Hey Stephanie, since your RV toilet water line would use 1/2 inch NPT fittings the correct cap you'd need is the part # LSB25XR and it would be capped off!

expert reply by: Jameson C

Stephanie M.

6/9/2026

Does that part screw directly into the cut off water line? Or it should it fit into the fitting on the elbow connector? The fitting on the elbow connector seems more like 3/4".

Jameson C.

6/10/2026

@StephanieM Without seeing the setup it's hard to say but basically you are going to cap the line that normally runs to the toilet so that the water pressure does not make it past that line. Now you could very well have a different size fitting but the standard for RV toilet water feed lines is 1/2 inch NPT so worst case scenario you source a 3/4 inch NPT cap and use it but that's not something we carry.

Stephanie M.

6/10/2026

@JamesonC I have pictures I wish I could send you. What about the fitting that's on a low point drain? Like the whole thing that's attached to the bare tube. That would work, wouldn't it (as the fitting that's on the tube that attaches to the toilet would easily come off)? Do you carry that?

Jameson C.

6/11/2026

@StephanieM If you want you can send me pictures at [email protected] It sounds like you have PEX tube that you are wanting to cap off which for that you could use the part # FL92VR.