Prevention

Keep the funk from moving in.

An RV is a small, sealed box with plumbing that sits still for weeks. Odors win when water dries, tanks go anaerobic, or air stops moving.

Black tank, on a cadence

Leave 3–5 gallons of water in the tank after a dump. Add treatment rated for your system (enzyme or chemical — pick one and be consistent). Don’t travel with a bone-dry black tank unless the manufacturer says otherwise; slosh without water bakes waste onto sensors and walls.

Use plenty of water with each flush. RV toilets fail when people try to be “efficient” with a cup of water. The tank needs a wet, moving slurry, not a crust.

Gray tank and traps

Kitchen grease and hair are the usual villains. Wipe pans, use a sink strainer, and flush the shower with hot water after a soapy wash. If you store the rig, pour a cup of water into every drain so the P-traps don’t dry out and vent sewer gas into the cabin.

Move air, on purpose

A roof fan on low beats a bottle of spray. Crack a window when you cook or shower. If the coach is parked, a dehumidifier or hanging moisture absorbers in the bath and closets will do more than incense.

Fridge and food

Absorber fridges need airflow behind the cooling unit. Clean the drip pan. Don’t store leftovers through a two-week sit. If you smell ammonia-sweet chemical, stop using the fridge and see the fridge checklist.

Fresh water that doesn’t taste like hose

Sanitize the fresh tank seasonally. Replace the in-line filter. Stale water isn’t always “smell,” but it makes the whole cabin feel off — especially when it hits the water heater.