Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Malfunctioning after 2 years.

We installed these in our new home (built in 2010), with a manufacturing date on the units of March 2010. They go off for no reason as other reviewers have commented (often at about 2am). We even built our house new, so no left over smoke - I'm not sure what sets them off. I have reset them per the instructions and cleaned them with compressed air, again as the instructions advised, but they still randomly go off.While the house-wide alert is nice for a real fire, when they are repeatedly false alarms it's horribly annoying. Once these things go off, I'm up for the night. Last night (July 24, 2012) was the third time this has happened, just like another reviewer, so we are throwing these blasted things away and finding something different. BE WARNED SHOPPERS!