Every new RV owner dreads this one. Let’s just say it: nobody buys an RV because they’re excited to empty the toilet tank.
It’s easier than it sounds. Once you’ve done it a couple of times, it takes about ten minutes and it’s no big deal. Do it right and you won’t get anything on you. You also won’t have a smelly RV.
Know your tanks
Most RVs have three tanks:
- Fresh water tank. Clean water for your sinks, shower, and toilet.
- Gray water tank. Water from your sinks and shower.
- Black water tank. Everything from the toilet.
Some RVs have more than one gray tank. Your owner’s manual will show you where they are and where the valves are.
The valves are usually handles you pull out to open and push in to close. They’re often near the sewer outlet on the side of the RV.
What you need
- A good sewer hose with fittings
- Disposable gloves
- A separate hose for rinsing (not your drinking water hose)
- A clear elbow fitting is handy, so you can see when the water runs clean
Step by step
1. Put on your gloves. Every time.
2. Make sure both valves are closed. Check before you take the cap off. If a valve was left open, you’ll find out the messy way.
3. Hook up the sewer hose. Take the cap off the RV’s sewer outlet and attach the hose. Twist it until it locks. Put the other end firmly into the dump station or campground sewer hole. Many people put a rock or a weight on it so it can’t pop out.
4. Dump the black tank first. Pull the black valve all the way open. You’ll hear it drain. Wait until it stops.
5. Rinse the black tank if you can. Many RVs have a black tank flush hookup on the outside. Hook your rinse hose to it and run water until it comes out clear. If you don’t have one, you can fill the tank partway with water through the toilet, then drain it again.
6. Close the black valve.
7. Now dump the gray tank. Open the gray valve. The soapy gray water helps rinse the black water out of your sewer hose. That’s why you always do black first.
8. Close the gray valve.
9. Rinse and put away your hose. Rinse it out, drain it, cap the ends, and store it away from your fresh water gear.
10. Put a little water back in the black tank. Flush the toilet a few times to put a few gallons back in, with a tank treatment if you use one. This helps keep things from drying and sticking to the bottom.
11. Take off your gloves and wash your hands.
Mistakes to avoid
Don’t leave the black valve open at the campground. It seems easier when you have a sewer hookup. But the water drains out and the solids stay behind. They pile up and harden in the tank. Keep the black valve closed and dump it when it’s around two-thirds full.
Use plenty of water. Water is what carries everything out. A tank that’s too dry can clog.
Use RV toilet paper, or a toilet paper that breaks down fast. Regular thick toilet paper can clog the tank.
Never put wipes in the toilet, even the ones that say flushable.
Don’t trust the tank sensors too much. The gauges inside many RVs get confused and read “full” when they’re not, or the other way around. Get to know how long it takes your family to fill each tank.
Watch your drinking water hose. Never use it to rinse sewer gear. Keep the two hoses apart.
Where to dump if you’re not at a campground
Lots of places have dump stations: many campgrounds, some truck stops and gas stations, and some RV dealers. Some are free and some charge a small fee. RV apps and websites list dump stations near you, so check before you head out.
Never dump your tanks on the ground or down a storm drain. It’s illegal in most places and it’s bad for everybody.
You’ve got this
The first time feels like a big deal. By the third time, you won’t even think about it. Take it slow, follow the steps, and wear the gloves.
Next step: Make sure you have the right gear with our first RV trip gear checklist.