Kenmore electric range (ceramic top) mod 790.9641?

Error Code F40 is called the "Cooktop Lockout Error," which doesn't acutally tell you much. You can try shutting the power off to the range for about 2 minutes, then turning it back on and "re-programming" the range as described in the manual like when you first install it. If the error code is reproducible after that (i.e., it happens again), it might represent your circuit breaker being less than the optimal 50 amp circuit. (40 amps or less was fairly common in older range circuits, so if you replaced an older range with this newer one on the same wiring, it might be the problem). If it's not that, a call to the Kenmore people is in order.

Dwight Klettke
July 2008