A fluid sensing system and approach having a leak sensor. The leak sensor may output a signal when a fluid is detected. The signal may go to an alarm circuit which can sound a warning or alert. The signal may also go to a control interface of a piece of equipment, such as a water heater, to shut off the piece equipment in an event that it is causing a leak of fluid. Also, the sensing system may have a low battery sensor and indicator in case a battery supplying power for the sensing system is running low. The sensing system may be made of analog circuitry and discrete components.