Oven Temperature Not Accurate

Common Causes

A steady error in one direction — always too cool or always too hot — points at the sensor drifting or a calibration offset, both fixable. Wide swings around the set point suggest a weakening element or igniter that cannot keep up with the cycling. Uneven cooking between racks or sides is a different problem: heat is escaping past a worn door gasket, or the convection fan that should equalize the cavity has stopped doing its job.

Why Oven Temperatures Drift

The oven sensor is a thin probe inside the cavity whose electrical resistance changes with temperature. The control board reads that resistance and cycles the heat to hold the set point. As sensors age their resistance curve drifts, so the board holds the wrong real temperature while displaying the right one — the classic reason an oven bakes cooler year after year.

The door gasket matters more than most owners expect. A flattened or torn gasket leaks hot air continuously, so the area near the door runs cool while the back of the oven stays hot — producing trays that brown at the back and stay pale at the front, and longer cooking times overall.

Most electronic ovens include a calibration offset that shifts the displayed-to-actual relationship by up to ±35°F. When a reliable oven thermometer shows a consistent error, adjusting this offset can fix accuracy without parts — but a sensor still drifting will need replacement eventually, since drift continues.