A safety sensor device for an appliance detects burning conditions and shuts off power to the appliance. The device includes a sensor unit positioned near an exhaust of the appliance, and a relay unit connected along a power supply path to the appliance. The relay and sensor units are linked. The sensor unit includes a sensor for monitoring exhaust air from the appliance. The relay unit includes a circuit that electrically connects the appliance with a power source while in an ON state and electrically disconnects the appliance from the power source while in an OFF state, the circuit being responsive to the sensor unit to transition from the ON state to the OFF state if the sensor detects burning conditions.