Your Guide to RV Bathrooms and Plumbing

Also called clean water or potable water, this tank will supply water to your sink, shower and toilet.

This tank will gather all of the dirty water that drains from your sink and shower.

This tank collects all of the waste and sewage from your toilet. *In some RVs, all of the water from your bathroom (including the sink and shower) will drain into the black water tank as well.

Your RV toilet and plumbing systems are sensitive, so the 2-ply toilet paper that you use at home won’t work in your rig. To decrease your chances of clogged toilets and malfunctioning tank sensors, we recommend using 1-ply toilet paper. Scott® 1000 toilet paper is a great option and safe on septic tanks. And remember—never, ever flush sanitary products or wet wipes down your RV’s toilet.

To help prevent buildup, we highly recommend letting your grey tank get at least two-thirds of the way full before emptying it. Additionally, never let your black water tank get completely empty, as sewage can collect on the bottom and create some bad odors. There are septic-safe cleaning solutions and treatments you can add to your black and grey tanks to help with odor as well (see below).

It’s important to remember that your RV toilet should not be cleaned like a regular toilet. Using harsh chemicals can actually break down the seals within your plumbing system, leading to costly damages. One of my favorite ways to keep our RV toilet clean is simply using a mixture of hot water and Dawn dish soap. Before every trip, we fill our toilet through the external flush system and add a safe, gentle cleaning solution to our black water tank. Thetford is a great brand for both deodorizing and cleaning RV holding tanks.

If you’re like us, then you like to take your RV to warm, sunny climates. But sometimes, you’ll find yourself in colder temperatures, so it’s imperative that you take the necessary precautions to ensure that your water lines don’t freeze. If you find yourself in an area with cold temperatures, here are some tips:

Skirt Your RV. Putting a skirt around the outside of your unit is a great way to keep the underbelly warm—including the pipes and hoses—and protected from the elements.

Heated Hoses. Some plumbing and bathroom hoses come equipped with a heat strip that runs along the side of the hose. This strip can be plugged into a standard 110-volt electrical connection and will prevent the water and fluids from freezing.

Water Drain-Down System. These systems help your RV’s pipes drain faster and more conveniently. We highly recommend Lippert’s Floë Integrated Drain-Down System.

Disconnect and Drain. This might sound simple but it’s absolutely mandatory—when the temperature drops below freezing, disconnect your outdoor hoses and drain all sitting water. 

Make a point to regularly check all of the seals in your shower, toilet and sinks. If you notice any cracks or damage, replace the seals immediately. You can also use a flexible kitchen and bath silicone gel (available at most hardware stores) to help fill and patch any cracks.

Your RV tanks are built to help keep water and waste flowing in one direction. But if you fill your black tank to the maximum capacity, there’s a good chance the sewage will start to back-up, causing breaks and leaks between the tank’s seals.

Do you know how much water weighs? If you’re driving around with a full, 40-gallon freshwater tank, that’s an additional 334 pounds in your RV! If you’re not mindful of your RV’s total weight, the added weight from water and fluids can cause a slew of issues, including detached tanks and extra swaying if you’re towing.

You’d be amazed at how quickly things like rust and calcium deposits can build up in your pipes and water lines. Regularly check the end of your water systems by detaching the end of your faucets. This will allow you to clean the screens and improve water pressure.

There are two critical bathroom maintenance items we suggest adding to your RV: a water filtration system and a water pressure regulator. These two items will help ensure that you have clean, safe water and that you maximize the amount of water you’re using. The filtration system will also help keep harmful sediments out of your lines, and the pressure regulator will monitor the amount of water flowing through your pipes to prevent any bursting.

Try to keep your bathroom clean while you’re using it. This includes wiping things down and keeping your vents open to prevent mold and mildew. After every trip, we also recommend giving your bathroom a nice, deep clean, including the sinks, faucets, floors, and shower walls. Many RV owners actually use dryer sheets to clean their showers—they are strong enough to scrub soap scum and build up but won’t damage any of your bathroom surfaces.