Nighthawk Gas Detector

Why is our chance detector goes off? We live in a condo unit, and the gas detector just went off, but then when you reset it, it was fine. He left before when I was overcooking. We only heat and electricity, so no propane for the advance off ..... Is it fair to be bugged?

I placed it here because people are very helpful and I got no response from the home and garden.

When ours did it was as simple as changing the battery.