"From the manufacturer:
Vac/Check cannot be installed in an inaccessible location where venting of water from device during normal operation causes damage. It must be installed in an easily accessible location to end user."
Venting of water? Do they mean when it fails? I thought it should only have air going through it normally. Guess they dropped the ball on mine; its under the sink (easily accessible) and when it decided to malfunction, the floor and everything below it got wet. Think the damage will be evident someday.