The following is a reprint from our Ask the Expert feature on AcmeHowTo.com:

Question: I have a crosley range, model #cg3478xra, when the wife tried to use oven she would set the tempature at 350 degrees the oven burner would not fully light, she would smell gas. Called crosley repairman, he replaced oven igniter, today she put a dish in the oven to bake at 350 degrees for 1 hour and is usually dne 1 hour. It took 2 hours 50 minutes. She put her thermonter in the oven, set the oven 350 degrees and waited for it to preheat, the oven read at 350 degrees and the thermomter read between 300 and 320 degrees on two differnt times . Whats the problem?

Answer: The problem you described I would have first diagnosed as some clogged gas jets. They can be cleaned with a toothpick. Generally, it either ignites or it doesn't. Some units have split jets and so you need two ignitors, that may have been your case.

As to the problem now, first this: An oven doesn't heat to 350 degrees and then just stay there. It heats to 350 or so and then it drops down to 325 and then heats back up to maybe 375 and then drops back down to 325 and repeats over and over. So when you check the temperature, it is depends on when it the cycle you checked and it depends whether you measured at the top or bottom of the oven and how long you waited since you last opened the door. In other words, you shouldn't expect the thermometer to read 350 all the time, when you have the oven set to 350.

If it is heating to 320 peak, then you may just need to adjust a nut on the control knob to turn the pointer the correct temp zone. In other words, if 350 is really 320, loosen the calibration nut and move the knob so it points at 320.

As to the temperature being dramatically too low, did you open the oven a lot just to make sure it was lighting? If so, that drops the temperature down a lot every time you check.

If all the jets are lighting and you don't smell gas, then the issue is with the temperature control or the temperature probe bulb inside the oven. The control either need to be adjusted or replaced or the temperature probe bulb is not properly in place (the repair person may have knocked it loose), or it is damaged and needs to be replaced.