Take off the cover and it cries, "Ouch, you idiot."
Try to replace the filters. It deeply sighs and sternly says, "No, you're doing it wrong again."
Anytime you walk by it utters, "Don't touch me you big oaf."
The serviceman should be able to get all sorts of phrases coming out of the thing.
After a couple years on the job he'll get tired of the whole lot and find pleasure in some new little hobby that takes all his time, keeps him coming home late, and not servicing your device anymore.