Emptying the Black and Gray Tanks

First a couple of warnings. We have included special RV toilet paper which is absolutely necessary to use because it breaks down quickly and won’t clog the tank. You can purchase additional RV toilet paper at Walmart, it’s only $5 for eight rolls.

The only things that can go in the toilet are human waste and RV toilet paper. NOTHING else can go down there. We have a trashcan in the bathroom with a lid for wet wipes, tampons, pads, wrappers, Q-tips, finger and toenail clippings, etc. If any of these things make it into the toilet and clog it, there may be fees that come out of the deductible to cover the additional work of removing the clog. We have provided plenty of extra bags for this trash can so if it fills up quickly, you’ve got a ton of extra bags available.

If you are parked at an RV park, DO NOT hook up the hoses and open the valves and leave them that way thinking you can just have the black tank empty continually – THIS DOESN’T WORK. The tank needs to fill with solids and fluids so the fluids can dissolve the solids which will prevent clogs and make emptying the tank easier. If you drain all the fluids, the solids will drop into a dry tank creating a horrifying solid pyramid that will dry out and create a massive clog problem that could incur additional fees from your deductible to fix.

DO drain the black tank once it has reached 2/3 capacity and follow these steps below precisely.

The supplies you will need to empty these tanks are contained in the black and yellow bin in the garage which is easily accessed on the rear left side of the vehicle. There hoses you will need are inside the rear bumper (one on the left and one on the right).

If the place to dump is near the RV, you may only need one hose but for longer distances you can connect both together to reach 20’ away.

Put on some gloves

Put on a pair of the included gloves to keep your hands fresh and clean throughout this process. They are located in the black and yellow bin in a Ziplock bag.

Attach the hose

In the black and yellow bin, get the clear plastic piece with the valve (Valve #3) and hook it up. Make sure all connections are firmly attached or you will receive a shower from hell.

If the drain is less than 10’ away, you will only need one hose, which can be removed from the left side of the bumper. Another hose is located on the right side if needed.

Hook up the appropriate-sized hose and make sure the other end of the hose is properly affixed to the sewer port where the waste will go. Please look carefully at the image below.

There is a black hose support that sits under the hose and allows it to maintain a gradual slope for when the tank fluids drain so they flow completely out and don’t get trapped in a sagging hose.

opening the black tank valves

First, open the valve on the right side of the RV (Valve #1) and the black water tank will begin to drain up to the point of Valve #2.

Return to the left side of the vehicle and open the second black water tank valve (Valve #2).

By opening this second valve, you will see the materials of the black tank fill the clear plastic area. Then, finally, slowly open the valve on the clear plastic unit (Valve #3) while keeping an eye on the other end of the hose and make sure the contents are draining properly.

While this is going on take the black hose, hook it up to the spigot and run it through the left side bedroom window and into the bathroom. Make sure both ends of the hose aren’t leaking when you are doing this.

Flushing the black tank

Keep an eye on the transparent part of Valve #3 because you can watch it to see if the tank is done draining. Once the black tank is finished draining, there will still be “residue” to flush out. Think of emptying a glass that you just drank a smoothie out of. There is still “stuff” stuck to the bottom and sides, but if you stick it under the faucet and flush it out a couple of times, it will be relatively clean. That’s what we’re going to do to the black tank (I hope I didn’t ruin smoothies for you).

Once the tank is done draining, close Valve #1 on the right side of the vehicle. Take the blue bucket with the liquid Dawn and Borax up to the bedroom and set it aside. Then check to make sure the water pump is set to OFF (it is located on the top left of the panel under the kitchen counter across from the cabin door).

Next, fill the blank tank with water from the black hose from the toilet. Simply look down the toilet and wait until the water reaches the top of the tank, which is also the bottom of the toilet pipe. WARNING: Stay with that hose the entire time!

When the black tank has been filled, return back to the left side of the RV. Open Valve #1 again and the tank will drain a second time and you’ll notice that the water is cleaner. Repeat this process at least one more time or more if there is still residue coming out of the tank.

Finishing off and prepping the black tank

When satisfied that the tank is washed out:

  1. Close Valve #1 and Valve #2.
  2. Fill the blue bucket halfway with water.
  3. Take the box of Borax and pour about a half cup into the toilet bowl with the valve closed (the area above the toilet bowl hatch holds just approximately 1/2 cup).
  4. Push down the flush pedal and open the hatch to drop the Borax into the tank. With the hatch still open, squirt about a 1/2 cup worth of liquid Dawn down the toilet (about 2-3 long squirts will do).
  5. Dump the water in blue bucket down into the toilet.
  6. You can return the hose, bucket, and its contents to the garage.

Emptying the gray tank

Return to the left side of the RV and then open the small gray tank valve (Valve #4). Once the gray tank is finished draining, you can close the gray tank valve.

Disconnection and finishing

Disconnect everything and spray the ends down with the 10% bleach water spray and return it to the bin just like you found it. Make sure everything is back in the bin like it was originally. Make sure that all 3 valves are closed and the cap is replaced! Dispose of your gloves and lock the hatch.

TIP: Always replace the hoses with the hooked ends facing outward, it is easier to grab and pull them out that way.

Dumping just the gray tank

Never hook up the hoses and simply let the tanks continually drain.  This will cause liquids to drain but scum to remain, dry out, and potentially clog the plumbing. 

You always want the black AND gray tanks to fill, then drain when they are about 2/3 full. 

The one sure way to know if the gray water tank is full is that the shower will not drain and some water may even rise up out of the shower drain so keep an eye on it. 

If the gray water tank fills up before the black water tank and needs to be emptied, grab some gloves, hook up the hose from the bumper (without the clear part with the valve, Valve #3) and flush the gray water tank by opening Valve #4 on the left.

Be sure to close Valve #4 when the tank is done draining. If you are still staying at your location, you can leave the hoses attached but make SURE the Valve #4 is closed so the tank can fill again. Then, you can simply open the valve whenever the tank is 2/3 full again. 

When you are ready to leave, spray down the connections and hoses with the bleach water sprayer and put hoses and gear back into their locations.