This is probably the most asked question (in one form or another) from new RV owners. How to avoid any dirty little mishaps, because dumping the tanks doesn’t have to be a dirty job, if done right.
List of Equipment Needed
- Sewer hose with attachments (make sure hose has no holes in it)
- Clear sewer hose elbow with an angle (45 or 90 degrees) for your particular system
- Garden hose (not your freshwater hose)
- Disposable gloves
Know Your Gate Valves
Your first step is to identify the Gray Water and Black Water gate valves on your trailer or motorhome. Every RV has a different setup, but these valves will most likely be located close to where your freshwater is hooked up. Here’s what one may look like. Each RV is a little different from one RV to another.
In some RVs, the black water tank pipe is larger than the gray water, but that is not always the case. Most are labeled and have a handle to pull the valve open and push it closed.
You’ll notice that the two valves are located close to where the plumbing for both tanks come together. There is a cap below or between the valves. This is where you will hook/connect your sewer hose.
Before you take that cap off MAKE SURE BOTH GATE VALVES ARE CLOSED!
Never open either gate valve before connecting the sewer hose or you’ll be filling the open space between the cap and the gate valve with black water and/or grey water. To remove the cap, rotate the tank lid counter clockwise (off) and set the lid aside.
Important note: is to make sure your air vent in the bathroom is closed and turned off when dumping the tanks. Otherwise, you will be pulling some odors that aren’t too pleasant through the bathroom, and they won’t dissipate very quickly.
Gravity Always Wins
Because ‘waste’ flows downhill, make sure the sewer hose attachment site is uphill from where the sewer hose will dump its contents (at a dump station or septic tank). Many RVers with full hook-ups (meaning they have electricity, water, and septic) at a campsite use a sewer hose support to create a downward slope to the sewer dump.
Depending on the RV set up, you may need to attach a 45- or 90-degree clear sewer hose elbow to the “RV” end of your sewer hose, then hook the hose to the plumbing below the gate valves in your RV where the tank cap came off. Once your hose is attached, put the other end in the dump station or septic hole at your campsite. Typically, a 90-degree elbow is attached to the dump station or septic side of the sewer hose. I would suggest placing a big rock on top of that end of the hose, so it cannot come out of the hole while dumping (this will help you to avoid any unhappy messes!). You’d be surprised how often the sudden rush of fluid and waste will pop the hose out of the septic hole.
Now you are ready for the action! Open the black tank valve and let it completely empty through the hose into the sewer. You’ll know it’s finished by looking at the clear elbow attachment.
When the blank tank is empty, close the black tank gate valve, then open the gray tank valve and let it empty, as well. By emptying the black tank first, the gray tank you are, in effect, helping to clean the sewer hose with the shower and dishwater stored in the gray tank.
Once both tanks are empty, close the gray tank gate valve, then you can do one of two things:
- If you have a clear elbow attachment with a sewer tank rinser, then attach a garden hose to it (NOT your freshwater hose), open the black tank gate valve and turn on the hose to rinse the inside of the black tank and sewer hose. Close the valve when water runs out clean to the septic, open the gray tank gate valve and clean that tank, as well.
Then move on to #2:
- If you do not have a sewer tank rinser on your elbow attachment, or if you do and after you’ve completed #1, make sure both tank gate valves are closed, unhook the sewer hose from the RV, leaving the other end in the sewer hole at the dump station or campsite. Rinse the inside of the hose thoroughly with a garden hose (NOT a freshwater hose).
When your sewer hose is clean, collapse it and put it in a plastic trash bag or in your sewer hose storage compartment. Put the tank cap securely back on the plumbing outlet in your RV, store your garden hose away from your fresh water hose, and wash your hands thoroughly.