A gap between what the oven dial says and the actual temperature inside is common enough that most ovens include a built-in way to correct it — usually called offset or calibration. Before assuming a part has failed, an inexpensive oven thermometer will tell you exactly how far off your oven runs, which is the first and most useful diagnostic step.
Testing the actual temperature
- Buy a simple oven thermometer
These are inexpensive and far more reliable than judging by baking results alone, since so many other factors affect how food turns out.
- Place it in the centre of the middle rack
Preheat the oven to a common baking temperature — 350°F (175°C) is a useful reference point — and let it fully preheat and settle for at least 15–20 minutes.
- Read and record the actual temperature
Check it a few times over several minutes, since most ovens cycle slightly above and below the target rather than holding one exact number.
- Repeat at a second temperature
Testing at both a lower and higher setting confirms whether the offset is consistent across the range or worse at one end.
Recalibrating the oven
Most ovens built in the last couple of decades have a hidden calibration setting, usually accessed by holding a combination of buttons on the control panel for several seconds — check your owner’s manual for the exact sequence for your model. This lets you enter an offset (for example, +15°F) that the oven then applies to every setting going forward.
When it points to a real fault
| Pattern | Likely explanation |
|---|---|
| Consistent offset in one direction (always runs hot or cold by roughly the same amount) | Normal — calibrate and move on |
| Offset that changes unpredictably between bakes | Points toward a failing temperature sensor rather than a simple calibration issue |
| Oven overshoots significantly then swings low, repeating in large cycles | Sensor or control board issue rather than a fixed offset |
| Large gap (more than about 25°F / 15°C) even after recalibrating | Worth having a technician verify the sensor before living with the offset |
When to call a technician
If the offset is unpredictable rather than consistent, or recalibrating does not bring it into a reasonable range, have a technician test the oven’s temperature sensor and, if needed, the control board.
Stop and call a qualified appliance technician or electrician if you find scorched or melted wiring, smell burning, see water that has reached electrical components, or if the fault returns immediately after a repair. Never bypass a safety device — thermal fuses, door interlocks and flood switches fail for a reason, and defeating one converts a broken appliance into a fire or flood risk.
