Without fuel, the oven does not heat. If the flames are low or do not light, check the supply valve, which is usually at floor level behind the stove. Natural gas is supplied by a pipeline. If the stove operates with LP gas, an empty tank prevents the stove from operating correctly.
Overheating of the burner causes corrosion in the tubes that form the base for the flames. These obstructions prevent the flame from burning evenly and increase carbon monoxide production. Many obstructed burners are easy to clean; however, you should replace those with holes rusted through the assembly.
The ignition system is located near the back of the stove, alongside the burner. If there is no flame on systems with a standing pilot, the burner does not ignite. Similarly, if the electronic ignition does not spark or glow, it does not light the burner. Thermocouple problems are common reasons why pilots do not light.
Turn the oven to any temperature above off and below broil. It should light within 30 seconds with a full flame. Faulty safety valves cause weak flames and require replacement.