Another thought crossed my mind today (yes, I have one).....I set my CPAP on the floor. If I put it on the bedside table or higher (as in the motor home) I get a LOT of water flowing back. It makes me feel like I'm drowning. It's reasonable to me.....water flows downhill!!! I don't have it sitting directly on the floor...with 2 cats, there's too much dust and cat fur. DH made a little table for it!