If the oven isn't heating to the baking temperature you set — it's too hot or not hot enough — the oven temperature sensor could be malfunctioning. Or the problem could be with the oven control board, which controls oven functions.
Some wall ovens have a relay control board that's separate from electronic control board. The relay board has the electrical relays that control the oven elements or burners. A stuck relay on the relay control board can prevent the oven from baking properly.
Wall ovens that have dial controls use an oven control thermostat to control oven temperature. You may be able adjust the thermostat to fix a baking problem when oven temperature is off by 15 degrees or less. If the actual temperature differs from the set temperature by more than 15 degrees, you may need to replace the oven control thermostat. (Note: The temperature adjustment limit varies among models. Some models have controls that allow you to adjust oven temperature up to 30 degrees in either direction.)
A failed bake or broil element in an electric wall oven can cause baking problems. A weak or damaged bake element won't heat the oven properly. If food isn't browning, the broiler element or burner might be at fault; many ovens activate broiling briefly to brown the top of baked dishes.
Many gas wall ovens use a glow-bar igniter to light the bake burner. A weak igniter may light the burner during the preheat mode but won't continue to ignite the bake burner properly in the bake mode. You may need to replace the igniter if it fails to light the oven burner consistently.