(Dodge County) Fall is here and officials say it’s a good time to get your furnace checked before it gets cold. Alliant Energy spokeswoman Annemarie Newman says you should at least take a look at your furnace air filter. She says if you have not looked at that filter in a while, it’s probably dirty and you do not want to leave it in there when windows and doors are closed. Newman says getting a furnace check up by a professional can help prevent a breakdown when it’s cold outside and you need that heat running. It can also spot potentially hazardous problems like leaks or improper ventilation.