how can i fix my baumatic electric oven b180ss?

Sounds as if your cooker element has blown. It lies behind the back plate over the fan. Four cross head screws remove this plate then three fix the round element to the wall. When element is loose CAREFULLY pull off the three wires and fix them with some sticky tape or they may fall behind & you have to remove the oven and its back cover to get at them! A new element is £25 at
http://www.ekmpowershop.com/ekmps/shops/elerep/index.asp?function=DISPLAYPRODUCT&productid=68

M Gilbert
January 2006