AIR QUALITY SENSOR/INTERRUPTOR

An air quality sensor and interrupter system includes an air quality sensor to measure the air quality around a gas appliance and an appliance shut-off device to turn off the gas appliance in response to a signal from the sensor indicating unsafe air. An exhaust can also be activated to remove the unsafe air. Unsafe air can be indicated by a measurement of 18.5% or less oxygen in the air. If the sensor fails, an alarm can alert the user and the appliance shut off until the sensor is replaced or repaired. A bypass allows the user to keep the appliance turned on, but only for a limited amount of time. The user can keep utilizing the bypass to keep the appliance turned on for extended periods of time.