The 5 most common part(s) or condition(s) which cause the symptom Oven won't heat are listed below starting with the most likely. Check or test each item and watch any available videos.
RepairClinic Item # 12872
Even though the oven igniter may be glowing, it may be too weak to allow the gas valve to open. If the oven won't heat and the oven igniter glows for more than 90 seconds without igniting the gas flame, the oven igniter should be replaced. This is the most common part that fails when the oven won't heat.
Although not as common, if the oven won't heat it is possible that the appliance is not receiving proper voltage. Electric ovens require 220 volts of alternating current. If for some reason the appliance is receiving significantly less, the oven won't heat. Check for proper voltage using a volt meter at the socket where the appliance plugs in. For more information on this see the How It Works video above.
If the oven won't heat, there might be a burnt wire supplying power to the bake element. Sometimes the wire supplying power to the element burns out right near the element itself. Check for this by just looking at the wires leading to the element. If they're burned out it is usually easy to spot.
RepairClinic Item # 1465761
If the oven won't heat the oven thermostat might be defective. Although this is not as common, it is possible that the oven thermostat contacts have burned or shorted open. The oven thermostat is difficult to test because the oven wiring diagram often doesn't illustrate each of the contacts and which should have continuity. If the oven thermostat is defective it usually has to be replaced.
RepairClinic Item # 300
The oven safety valve works with the oven igniter to provide gas to the burner. If the oven won't heat it is possible that the oven safety valve is defective. However, this is very rare. Most often, the oven igniter is too weak to allow the oven safety valve to open. If the oven won't heat, check the igniter first.