Welcome to FixYa! I am the expert who chose your issue to resolve. Rival does not offer the ability to replace parts online so you will have to call customer service. However, I've drilled down to the Crockpot area of their site to make it easier for you. Just click on the following link:
http://www.crock-pot.com/CustomerService.aspx?id=rptThanks for using FixYa!
P.S. - If you find that the solution/answer I provided led you to, or resulted in a fix, please close the ticket with a FixYa! rating. I would be very grateful for your show of appreciation. If it hasn’t, please do not assign a rating just yet. Please post back as to what steps you took, results, etc, and I will try to assist you further as best I can. I am at your service.