The Frigidaire Professional series oven/stove is several years old and was taking up to 45 minutes to preheat the oven to 350 degrees. The problem could have been caused by several items not working properly. I decided to replace the oven probe, lower oven igniter and the lower burner. Following the how to videos from Appliance Parts Pros, I was able to replace all three items within an hour or so. I have limited knowledge with appliances but this was a snap with the aid of the videos and saved me several hundred dollars in repair bills. The videos were easy to understand without a lot of technical jargon. Thanks to Appliance Parts Pros.