Product review (5 stars): Center burner replacement on Kitchenaid Double Oven (KGRS505XSS)
Our center oval burner knob would not turn and completely seized.  We rarely use this burner so not sure why this burner valve failed after 4 years from oven purchase date.  Anyway, delivery was very quick and took about 45 minutes to replace.  No instructions included, but it's an easy replacement and an original Whirlpool part like most Kitchenaid appliances since Whirlpool is the parent company.