Jack W San Leandro , CA January 31, 2015 Appliance: General Electric Free Standing Microwave JVM1870SK03 Ge Microwave Jvm1870sk03: I got an "time to change charcoal filter" message on the microwave screen it was already in house when i purchased it there was no filter. How to replace Charcoal Filter. After going to Appliance Parts Pros website, and reading the options available and recommended based on how the microwave is installed and vented, I decided the charcoal filter was the way to go. 4 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes