Why it matters
An overfull tank can back up into the van, and a neglected cassette is simply unpleasant. It's a two-minute job at any proper disposal point.
How to do it
- Check the level gauge before setting off on a longer drive.
- Empty at a designated waste point only - never onto open ground.
- Rinse the tank through with clean water afterwards to reduce residue and odour build-up.
How often
Every few days of active use, or before/after every trip.
Rough UK cost
Usually free at campsites and service points.