We've owned this oven for the past 5 years. In the past year it can be sporadic on how long it takes to bring the oven up to temperature. It started with just the top oven, but now the bottom oven is acting up as well. As an example, it just took about 45-60 minutes to bring the oven up to 350 degrees.
This is a Kenmore Elite 30" Dual Wall oven, bought from Sears Canada. The model is C970-419232 which I can't find at this site but which comes up as an Electrolux model on a google search.
Any ideas what the problem could be? I'm thinking either element or thermostat, but that's just a guess.