I have a Tappan gas oven (model 12-2299-10/06) which was installed over 18 years old. Within the past 6 months, the oven is not reaching the desired temperature. According to the thermometer I placed inside the oven, the temperature is off 50 degrees (too low).

For over 2 hours tonight, I made an attempt to recalibrate the temperature. After pulling off the control dial, the two small screws on opposite side were exposed. I turned the screws either clockwise and/or counterclockwise and waited 15 minutes to see if the temperature increased. I tried different variations to the screw adjustment procedure. Unfortunately, I was not successful in achieving the temperature noted on the inside oven thermometer. I learned about the calibration procedure by searching the Internet. However, the instructions about what direction to turn the screws varied from one tech to another.

At this time, I'm ready to leave the temperature calibration fixes to a pro. Does anyone have a service or owner's manual for my oven? Is calibration a difficult task? I think so! I also understand the temperature issue could be related to a broken part.

Any assistance you can offer would be greatly appreciated! :)

one more thing, taking a temp reading takes time and patience. 15 minutes is not long enough to get a true oven temp reading

Let the oven preheat, then check you oven thermometer 20 minutes after it has preheated. this will give you your best temp reading....let us know what you find.