According to Repair Clinic, the most common reason that an oven fails to heat is due to a problem with the igniter. Electric and gas ovens have igniters. The igniter is an essential element that helps the oven turn on and become hot. When the igniter fails, it must be replaced.
All ovens have an igniter element that controls the oven temperature. Normally, when the oven is turned on, the igniter activates and causes either a gas or electric valve to allow heat to enter the oven. In gas ovens, the igniter lights up a stream of gas.
There are several other problems that may cause an oven to stop producing heat. If the problem is not the igniter, the bake and broil elements, the oven's circuit board, wiring, pressure regulator, thermal fuse or thermostat may be at fault. A technician checks for these issues, diagnoses the problem and corrects any issues with the consent of the owner.
When the oven is powered by gas heat, it is important to be alert to the smell of gas. Gas can quickly fill the kitchen, which is dangerous. Completely turn off an oven that is not heating properly and contact an oven appliance repair technician to diagnose and fix the problem.