[vmc4820]

You may want to call DRV. We had a problem with ours in the beginning because one of the grommets had cracked. They gave me an extra set of 4 since these do crack and break over time especially if you are not careful when you lift the grate out to clean. If you try and clean by only taking the grate out part way and not straight up, the grommets will also crack. Good Luck.