RV Toilet Leaking? It’s Probably the Valve

There’s always something to fix in the RV. Most of it’s minor—tighten a hinge, reset the fridge, figure out why the water pump’s acting weird again. But when the toilet starts leaking, it feels like a bigger deal. Messier. More annoying. And honestly, kind of intimidating the first time. So when we pulled into the campground, hooked up to city water, and I heard that familiar drip, drip, drip behind the toilet… I knew exactly what we were dealing with.

I walked in and, yep—the floor was already soaked.

What makes it funnier (or not) is that this exact thing happened two years ago. The exact same weekend, and the exact same campground. Luckily, we’ve been through this enough times now that I don’t panic anymore. (Actually, I joke that I’m going to start a side hustle as an RV plumber).

I turn on the sink to relieve the pressure from the toilet line, shut off the spigot outside, grab a towel, and go into problem-solving mode. And almost every time? It’s the same issue: the little valve on the back of the toilet.

We have a 2020 Rpod-192 with a Thetford 31687 Aqua-Magic V toilet. I actually called two mobile RV repair companies just to see how much they’d charge to come fix it—out of curiosity. Both quoted over $300. At that point, you might as well replace the whole toilet (a replacement is under $200).

But you don’t need to do either. This is an easy fix. I’ve even done it myself while five months pregnant, with no plumbing experience, and a basic tool kit.

Tools you’ll need

• Phillips head screwdriver
• Adjustable wrench
• Optional: channel locks or pliers if you run into a stubborn fitting (we didn’t need them—just the wrench worked fine)
• Gloves and cleaning supplies (it’s can be dirty back there)

Step 1: Figure out what toilet you have

Look behind the toilet bowl for a sticker or engraved label with the brand and model.
Ours says: Thetford 31687

Step 2: Order the valve kit

You can buy the official Thetford part at Camping World or other RV stores—but it’s usually double the price. This time around, we with an aftermarket version that’s worked great and saved us some cash. Plus it’s built to withstand freezes and cracking.

RV Toilet Water Valve Kit – Freeze Resistant & Leak Resistant by Vypart
Here’s the kit we purchased from Vypart, and it fits a few of the Thetford Aqua-Magic V toilet models. It’s under $20 on Amazon, and we now keep one in the RV at all times.

Step 3: Remove the toilet

Yep, the whole toilet has to come off.

• Remove the plastic caps at the base and unscrew the two bolts holding it to the floor
• Disconnect the water line (if you haven’t already)
• Carefully lift the toilet straight up and set it aside somewhere clean

Just a heads-up: it’s probably gross underneath. Take the chance to scrub the floor, wipe down the bottom of the toilet, and maybe even replace your toilet seal if you have an extra one handy.

Step 4: Replace the valve

With the toilet out, you’ll have easy access.

• Use a screwdriver to remove the screws holding the old valve
• Pop it off, clean around the area, and screw in the new one snugly (don’t overtighten)

Step 5: Reinstall the toilet

• Set the toilet back over the bolts
• Tighten it down evenly (don’t overtighten or crack the base)
• Now reconnect the water line
• Turn the water back on slowly and check for leaks

If everything’s tight and dry—you’re done.

RV Toilet Leaking Again? Keep This Part on Hand

Fixing things in the RV is never fun, but this one’s not hard—and once you’ve done it, you’ll wonder why you ever thought about paying someone else. (You’ll also feel weirdly proud of yourself for pulling it off.)

We’ve replaced this same valve more than once, and every time it happens, I’m just glad we had a spare. Toss one of these kits in your storage bin and save yourself the scramble. If your toilet starts leaking again, check the valve first. It’s almost always the culprit—and now you’ll know exactly what to do.

Heads up: This post contains a few affiliate links. If you click and buy, I might earn a tiny commission—like, enough for a gas station coffee. It doesn’t cost you anything extra, and I only link to stuff we actually use in our RV.

New to RV life and not sure what’s worth buying? Check out my RV shopping lists with the essentials, small upgrades that make a big difference, and the gear that’s actually earned its place in our limited storage.