How long your gas detector will last depends on several factors, including its build materials and quality of construction. Typically though, most devices last from three to five years, but there are those that work for up to ten years with no issues. Of course, more expensive models should last longer as they’re made of better-quality materials and are sturdier. That said, price doesn’t always equate to quality, so make sure you’re buying from reputable brands regardless of the price.