Know the Symptoms of a Bad Ignitor.
Gas ovens are preferred for their cooking precision. However, when an ignitor begins to go out, the temperature control becomes erratic.
Aggravating as it may be, this is actually your ignitor's way of telling you to replace it, before you're left with an oven full of raw food.
First things first...
Before jumping to conclusions, it's always best to dot your i's and cross your t's.
Make sure the oven is plugged in, getting power, and the gas valve is open. If you have an older oven with a mechanical timer, make sure it hasn't been accidentally bumped off the manual setting.
If all that checks out, and the oven still isn't firing up, then the ignitor's probably to blame.
But, my ignitor still glows...
Even if your ignitor is still producing that pretty, orange glow, it doesn't mean it's working properly. Without going into the technical details, basically as the ignitor gets older, the electrical current can't flow through it as well, and eventually not at all.
In fact, if it takes more than 3 minutes for the ignitor to fire up, it's most likely bad.