Cassette Toilet

A toilet with a removable waste container that's emptied at any sewer or restroom rather than at a dump station. Common in Class B and small Class C.

Also called: cassette toilet, removable cassette, portable toilet

A cassette toilet is a toilet with a removable waste container (the “cassette”) that’s emptied at any sewer connection or restroom rather than at a dump station. Common in Class B camper vans and small Class C motorhomes where space for a full black tank doesn’t exist.

How it differs from a standard RV toilet

Standard RV toiletCassette toilet
Waste storageBuilt-in black water tankRemovable cassette
Capacity25-50 gallons typical4-5 gallons typical
EmptyingDump station requiredAny sewer connection or restroom
RefillingAdd water + tank treatmentAdd water + cassette-specific treatment
FrequencyEvery 4-7 days for 2 peopleEvery 1-2 days for 2 people

How emptying works

  1. Open the cassette compartment (usually on the exterior of the RV)
  2. Pull out the cassette (handle on top, locks with a lever)
  3. Carry the cassette to a toilet or sewer cleanout
  4. Pour the contents in
  5. Rinse the cassette with fresh water
  6. Add cassette treatment
  7. Reinsert into the compartment

The whole process takes 5-10 minutes once you’ve done it once.

Why cassettes exist

In a Class B camper van, there’s no room for a 25-gallon black water tank, the plumbing to connect it, or the exterior drain port. The cassette occupies a 12” × 12” × 24” footprint and accomplishes the same job.

The trade-off is more frequent emptying. Cassettes hold 1-2 days of waste vs. 4-7 days for a standard tank.

Where to empty in practice

  • Campground restrooms — most campgrounds allow cassette dumping in the restroom
  • Public restrooms at parks, gas stations (ask first)
  • Sewer cleanouts at home (residential dumping is fine)
  • Truck-stop dump stations — yes, but inefficient (designed for larger volumes)

Brand notes

The standard cassette is the Thetford C200 series. Some pop-up campers use Porta Potti cassettes. Both are interchangeable in concept.