Plumbing failures and leaks usually happen unexpectedly and can cause severe damage. FloLogic System 3.0, the manufacturer says, uses a flow sensor coupled with a user interface to minimize or prevent the damages caused by such events. The unit monitors all water coming into the home and automatically shuts off if its flow exceeds a preset limit. Cost: $795, including keypad, power supply, cables, battery, valve, and flow sensor. FloLogic. 877-356-5644. Circle no. 106.