Is there by any chance a "keep warm" setting that is turned on? We had a Tappan range like that and it turns out, the timer had a keep warm setting and once turned off, it functioned properly again.

Well it's an oven, so there is a "warm" setting at the low end of the thermostat. But yes, that could mean that the thermostat is problematical. It's a lot easier to fix the heating element than the thermostat, though!

We had a newly installed oven with a similar problem - took forever to preheat and couldn't get above 300ish degrees no matter how long we left it on. It turned out the electrical wasn't connected properly so it couldn't draw enough power, and once that was identified and corrected it worked perfectly. So it's not just about having connectivity or not, but possible something in the electrical upstream of the heating element is restricting the total power it needs.

Well, it depends. My old GE oven is such that if you set it to Bake, the bottom element will glow but the top still gets hot enough to burn you but not glow. It may be that the lower element (if she is baking) has burned out but the upper is still 'warm'.

Also, some ovens have a 'Sabbath' setting that might do this. No cooking on the Sabbath.

Interesting idea about one element not heating. That would make a lot of sense. I'll check that out. Thanks.

OK, that's the answer. She tells me that when she turns it on, the upper element heats, but the bottom one does not. Now, I thought the upper element in an oven was just for broiling, but I guess it's used for baking as well in this one.