Cassette Toilet Operation

How To Use A Thetford Cassette Toilet

Some Flagstaff pop-up models come with a Thetford cassette toilet. The "cassette" in cassette toilet means the black water tank slides out the side of the camper (or in the case of the 28TSCSE, slides into the walkway of the camper interior) and can then be emptied at an RV dump station, a campground sewer system, a gas station restroom, an outhouse, etc. This is similar to the operation of a porta-pottie except that the top of the toilet (the seat and the fresh water tank used for flushing) is built into the camper.

Before filling the fresh water tank make sure the camper is level (otherwise the tank may not fill properly).

1. Open the cassette toilet access door on the exterior of the camper (or the interior cabinet for the 28TSCSE).
2. Rotate the fill-spout away from the camper to access the fill-spout cap.
3. Remove the cap and pour water (from a hose, pitcher, bucket, etc.) into the fill-spout.
   
   (Make sure the camper is level or water will not fill past the p-trap; further details )
   
   
4. Notice the glass vial on the side of the access area--it shows the water level in the fresh water tank. When the water level is ~1/2" from the top of the glass vial the tank is full.
5. Because of the fill-spout's p-trap design water will be stuck in the bottom of the fill-spout tube. Thetford smartly designed the tube to rotate on its axis to allow the excess water to pour out. Rotate the tube, pour out the water, rotate the tube back to its upright position, and replace the cap on the end of the fill-spout.
   
   
   
6. Close the access door.

A starter bottle of holding tank deodorant comes with every Flagstaff camper. In camper terms this is usually known as "the blue stuff" (although green and orange deodorants are also available).

Thetford warns against pouring deodorant into the holding tank via the toilet bowl or the flapper door in the holding tank because the deodorant could damage the rubber seal on the flapper.

Instead, remove the holding tank from the cassette toilet and pour deodorant into the emptying spout like this:

1. Open the access door.
2. Lift up on the safety catch that keeps the holding tank from sliding out of position inside the cassette toilet.
3. Pull the holding tank's handle toward you while still lifting up on the safety catch. The holding tank should start to slide toward you. (If it does not, check that the flushing lever inside the camper is in the "closed" position).
   
   
   
4. Remove the holding tank from the camper completely and set the tank on the ground.
5. Position the holding tank upright so the handle is pointing upward.
6. Rotate the emptying spout so it also points upward.
7. Remove the emptying spout cap.
   
   
   
8. Pour holding tank deodorant into the emptying spout cap. (How much? Thetford doesn't say. Their not-so-hot manual says: "pour the stated quantity of toilet fluid into the waste tank." The problem is, the rest of the manual doesn't state a "stated quantity." Mostly it comes down to how strong a "blue stuff" odor you want balancing out any other odors. Too strong a blue stuff odor? Use less blue stuff. Not a very technical answer, sorry.)
9. Pour 2 liters (~1/2 gallon) of water into the holding tank to mix with the deodorant
10. Replace the emptying spout cap, rotate the emptying spout into its original position, and re-insert the holding tank into cassette toilet. (Make sure the safety catch engages to hold the tank in place.)
11. Close the access door.

1. Turn the lever next to the toilet bowl counter-clockwise about 90 degrees to open the flapper between the toilet bowl and holding tank. (Thetford says that opening the toilet flapper before or after doing, well... one's business, is equally acceptable.)
2. Press the blue button to flush fresh water around the toilet bowl (The pump is designed to pulsate after an initial surge of water--this is normal operation even though it sounds a bit odd at first). NOTE: the camper must have 12V power to operate the toilet pump.
3. Close the toilet bowl flapper.

Next to the blue flush button is a small red light. When the red light turns on the holding tank is full.

To empty the holding tank:

1. Open the access door.
2. Lift up on the safety catch that keeps the holding tank from sliding out of position inside the cassette toilet.
3. Pull the holding tank's handle toward you while still lifting up on the safety catch. The holding tank should start to slide toward you. (If it does not, check that the flushing lever inside the camper is in the "closed" position).
   
4. Remove the holding tank from the camper completely.
5. Rotate the emptying spout away from the body of the holding tank.
6. Remove the emptying spout cap.
7. Empty the holding tank into an RV dump station, restroom toilet, outhouse, or other acceptable receptacle. (Notice a "vacuum breaker" on the far end of the tank. Depress the vacuum breaker to minimize the "glurg" effect while emptying the holding tank.)
   
   
   
8. Once the holding tank is empty you may want to rinse the tank with fresh water. For continued use follow the "Prepping the holding tank" section to fill new deodorant and water into the holding tank.
9. Replace the emptying spout cap, rotate the emptying spout to its original position, and return the holding tank to the cassette toilet.
10. Close the access door.

The cassette toilet is separate from the rest of the camper's water system and must be winterized independently from the standard winterizing process.

Instructions for winterizing the cassette toilet are found in the Cassette Toilet Section of the "Winterizing" page.

Most roads have a slight curvature to allow rain to quickly drain from the street. If you park the camper on the side of the road the camper will be at an angle due to this curvature.

Road curvature

The arm that swings out to fill the cassette toilet creates a p-trap. If the camper isn't level this p-trap could be above the level of the opening where you fill up the cassette fresh-water tank. Some water may go into the tank because of the pressure from the hose but most of the water will come back towards you and onto the ground.

P-trap height issue if the camper is not level

If the camper is level this problem is avoided completely and water will fill up and over the p-trap and into the cassette's fresh water tank as it should.

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