A stove thermostat controls the power that flows to an oven's heating element, allowing the oven to reach and maintain the proper temperature. The thermostat includes a bulb that senses the oven's temperature and turns the heat on as needed to sustain a consistent temperature.
Over time, the thermostat may lose its calibration, which affects the oven's ability to heat properly. Some ovens contain an adjustable thermostat that can be recalibrated, a step that is necessary if a thermometer shows that the oven's temperature is off by more than 25 degrees Fahrenheit. Faulty thermostats that aren't adjustable must be replaced.