I have a Thermador GGS30W cooktop with gas burners and electric ignition. On one burner, the ignitor is loose. I can ignite the burner if I push it into just the right position, but since it's loose it keeps slipping out of position. Can I get access to its back by removing the large nut in the middle of the burner? Or is there some other easy fix to put it in place. Ignitor is on the left in the photo. Thanks for your help!