I have a Thermador SEM302BP that was preheating to 325 tonight and it stalled out at 300. It now does not seem to generate any heat regardless of the setting (bake, broil, convection, etc). The display indications are normal in that it displays the proper elements and that it is preheating but the temperature never rises. The fan turns on and I beleive I hear clicking of relays periodically.

It doesn't seem like it would be a heating element since none of them are working. What should I look at... I'm a handy individual and am pretty sure I can repair this myself. Just looking for some guidance before I open it up and some guidance on if I can access things from the front or if I need to slide it out of the cabinet. (I'm the person who installed it almost exactly five and a half years ago.)