Heather S Rochester , MN June 07, 2015 Hadn't been properly cleaned in years Took off the vents to clean it good. Saw the charcoal filter. Needed to be replaced (had been 13 years) popped the new one in. While I was at it got a new grease filter which slides in easily. 3 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes