My wall oven (Whirlpool - Blanket O Flame Broiler) was not working.
So, I called a repair service to address the issue. The agent concluded that the ignitor switch is faulty and he replaced it. After that, the oven worked fine one or two times.

But then, when my wife turned the oven on, after a minute, the oven door almost burst open.
It was like a mini explosion inside the oven.

So, we called the repair service and the guy looked at it closely and may have adjusted something, but then we experienced the same thing again. I called again and the guy said that there is not much he can do. He said perhaps the ignitor switch and the heating element are not that compatible.

He suggested that I buy a new oven since this oven is 30 years old.