RV OWNER’S FIELD GUIDE · PLUMBING
Cassette vs. Black Tank Toilets
A common decision point on van builds and smaller rigs — here’s the real tradeoff.
Cassette Toilets
A removable waste tank you carry to a dump point rather than a plumbed-in black tank. Common in smaller rigs and van builds where space and weight are tight. No dump valve or macerator to fail, but the cassette itself requires manual carrying and emptying, and has limited capacity between empties.
Traditional Black Tank
A fixed tank plumbed under the rig, emptied at a dump station through a sewer hose. Higher capacity than a cassette and no manual carrying, but more plumbing to maintain (valve, sensors, vent) and the rig has to physically travel to a dump station, or use a macerator/portable tote to get there.
What to Weigh in a Van Build
Cassette systems are usually the simpler, lighter, lower-cost install for a build with tight space; a black tank system makes more sense for a build with room to spare that will see heavier, longer off-grid use. Composting toilets are a third option worth comparing with a certified installer before committing to a build layout.