Instruct: Classify Amazon reviews into positive or negative sentiment
Query: False alarms

I purchased this combo unit because I wanted a good unit that I wouldn't have to replace every other year. What I received was a unit that gave me explosive gas false alarms in the middle of the night. Since I work as a cumbustion engineer and knew that based on the fact that there was no smell, there was no chance that I was in a hazordous situation. It spent a number of nights in the garage so that I could go back to sleep.