I have a Jenn Air JGS8860BPDP gas oven. In the last week it started taking a very long time to heat up. Maybe 45 minutes to get to 400 degrees, but it's also not stopping. The digital read out on the front will keep moving past the desired temp. I haven't let it go to see how high it will get, and hitting cancel does turn it off.
The stove top burners work fine, as does the Broil function on the top inside of the oven.
After reading a number of posts I thought maybe the ignitor on the bottom of the oven might be an issue. I removed the bottom panel, set the temp for 300 and watched it heat up. It turned bright orange and ignited the gas, which was burning with both blue and orange flames. When I checked back in a few minutes, it had hit 258 degrees but there were no longer any flames. They returned soon after and I then watched as the digital read out on the front of the stove kept climbing past 300.
Any thoughts? Faulty ignitor, thermostat or something else?