The Kenmore oven's temperature is set to a factory setting that maintains proper heating temperatures. It is adjustable by pressing and holding "Bake" on the oven's control panel. Holding back allows you to reconfigure the oven by raising the temperature's calibration settings. Make temperature adjustments in minor increments to avoid overcooking your food.
A partially closed shutoff valve prevents the oven from heating properly, as the shutoff valve restricts gas from flowing from your home's gas supply line to the oven. The supply line is clear of obstructions and distributes gas to the oven within one to two minutes depending on the speed of your oven. The shutoff valve is located along a metal hose that links the back of the oven to the gas outlet that's poking from the floor or the wall.
A blown fuse or tripped circuit breaker will restrict your oven's ability to warm up, as the oven draws power from your home's power supply, even though it's a gas range. A blown fuse in your home's fuse box contains a black, sootlike coating inside of it when it is no longer functioning, or it will have a visibly broken wire inside it. Alternatively, a tripped circuit breaker's switch is flipped to the off or neutral position; correct it by flipping it back to the on position.
A slightly ajar door allows heat to escape from the oven, which considerably lengthens the preheat time. Check for loose hinges on the oven's door and make sure the door is completely shut to seal air out of the oven while in use.