, this freestanding range began displaying an F1 error message when using the bake mode, but the error didn't occur every time. A couple times, the customer said the range shut itself off in the middle of cooking, but it would start heating when bake was again selected. The infrequent nature of the problem can make it a bit more difficult to locate the failure, but if we put the signs together, (and read the tech sheet) we can at least do some tests and find out what isn't causing the problem.
According to the tech sheet for this model, the F1 is an indication of a keypad error, an internal communication error, or a temperature sensor error. Because the first two indicate a control board failure, and the third a sensor failure, I decided to test the sensor and see if it was working correctly. This way, I could eliminate the one component that is easy to test as being the failure. The wiring to the sensor and control board are easy to get to once the rear panels are removed. The probe can be checked while it is in the range, but by removing it, I can check it over a wider range to verify it's operation.
The temperature sensors used in most ovens and ranges are a thermistor type referred to as a PTC or Positive Temperature Coefficient. This simply means, as the temperature applied to the sensor increases, its resistance will also increase. This is the opposite of most thermistors we use in other appliances, but the concept is the same. For this sensor, I connected my meter leads and checked the resistance at room temperature. The resistance measured was about 1077 ohms which is about what I would expect based on the values given in the tech sheet. I then placed the probe in a container of ice water so I could test it at 32 degrees and I read 998 ohms. This too was about right so I concluded the temperature probe was working fine, leaving the control board as the cause of these intermittent fault codes.
I attempted to start and stop several bake cycles to see if I could get the F1 to appear, but the unit never failed for me. The customer wanted the problem repaired so we decided to replace the control board figuring they would know within a few days if that fixed the problem.
After disconnecting the power, I installed a new control board part # 316207511
I used the touch pad from the original board by simply pealing it off. Returned all the wires to their original locations and put everything back together. After a week of nothing from the customer, I decided to make a call to see if the range had been working properly and sure enough, all was well.