Hello, my name is XXXXX XXXXX X will help you with your oven. Your oven has a spark ignition system for the oven. It will try to light 3 times and if it does not light it will lockout. When it locks out the display still shows that the oven is on and it does not indicate a failure but the oven will no longer heat until it is shut off and started again. When the oven lights intermittently it can light the first time and come up to temperature but then later when it tries to come back on to maintain temperature it could lockout. I won't be able to give a specific repair but it is likely either a problem with the igniter or the position of the igniter or a gas/air mixture problem. You need to observe the oven burner lighting and see if the ignition is correct. It should click 3 times or less and be lite. If it tries for 4 seconds and stops for 30 seconds and tries again there is an ignition problem. You may not need any parts if it is an alignment problem with the igniter. I will try to give more specific information if you can tell me about what the oven ignition system is doing.