Whirlpool Oven Not Heating Properly

My electric Whirlpool oven seems to take forever to heat up. It takes about 1/2 hour to heat to 350. I tried 400 degrees today - took 45 minutes to get there. :confused:

I bake in the oven almost daily, and this is driving me nuts!

I don’t use Broil often, but the last time I tried, I turned it on for about 15 minutes and the oven was the same temp at the end as it was in the beginning…

I haven’t tried to use the self-cleaning feature (too many warnings that it is toxic to birds and moving a 200 pound bird cage somewhere in the house where she "might" be safe isn’t an option!) so I don’t know if that works or not.

I know there is a hidden element somewhere, plus an element at the top. Is it possible one or both of these is not working? If so, how do I find the "hidden" one so I can get my hubby to replace it? Or could it be something else.

It could be a number of things.
First check that the broil element is working usually during preheat both elements are used.