Hi Carol, good detective work checking with a thermometer and then trying convection. That test basically tells us what’s wrong.
Why it holds temperature on convection but not on Bake
Your Kenmore 790 range is built by Frigidaire. When you preheat on Bake, it uses both the top (broil) and bottom (bake) elements to get hot fast. Once it reaches temperature, the top element mostly stops and the bottom bake element is supposed to keep the heat up by itself.
Convection uses a different element behind the fan in the back wall. So if the oven reaches temperature, then cools down on Bake but stays steady on convection, my first suspect is a bake element that has failed or is failing. It looks like the oven was fine because the top element did the preheat work.
A quick check you can do
- Set the oven to Bake at 350°F and let it preheat.
- After the beep, wait a few minutes and look at the bottom element through the window (or open the door quickly).
- It should glow orange-red on and off as it cycles. If it never glows on Bake, it’s bad.
- With the oven off and cool, look closely at it for a blister, crack or burned spot. That’s often where it broke.
If the element does glow but the oven still drops, the next suspects are the temperature sensor (the thin probe on the upper back wall) or a relay on the control board. A sensor should read about 1,100 ohms at room temperature if you have a meter.
What it costs
A bake element is usually $30–$60 for the part. On most Frigidaire-built ovens it’s held in by two screws at the back. Turn off the breaker first, slide it out a few inches, move the two wires to the new one, and you’re done. If you’d rather have a technician do it, expect roughly $150–$250 total. At 8–12 years old, this repair is definitely worth doing.
Until then, convection mode is a fine workaround. Just lower the recipe temperature by about 25°F. If the element looks perfect and it still acts up, write back and we’ll go through the sensor test together.