 Best in Talk Radio. Your Aspen Fire Department reminds you to check expiration dates on your smoke and carbon monoxide detectors. Regular maintenance prevents false alarms. Replace the batteries annually and test them once a month. Also, did you know that most house fires start in the kitchen? Never leave cooking unattended and please keep a fire extinguisher in your home. Learn more at aspenfire.com. Your Aspen Fire Department. Protecting and serving Aspen for over 135 years.