My new wall oven with the hidden lower element will not bake lasagna properly, no matter what I do. The cheeses and sauce don't meld into the pasta well. It takes forever to get the center of the lasagna hot but the pasta noodles toward outer pan are cooked to mush. The middle remains cold for entirely too long. The edges of the lasagna turn very dark before middle gets warm. This is so upsetting because I make a wonderful lasagna but can't cook it correctly as I have many times before in double exposed element ovens. The instructions in the manual simply say you may need to turn up the temp alittle when using pyrex. Does anyone have any advise on rack placement and temperature adjustment with this type of oven? I cooked it according to recipe which calls for 30-40 mins, covered at 375. Then uncovered for 15-20 mins. I've been using the middle rack. I miss my old school oven! Thank you in advance.
First, purchase an oven thermometer so that you can verify your oven temp. Ovens can easily be off by 50 degrees or more. Lasagna is pretty forgiving. So exact temperature and time is not all that important. My process is similar...cook covered, then uncover. Pasta turning to mush might be a result of overcooked noodles before the bake, or the lasagna being too wet. It also sounds like you might be getting uneven heating. Try rotating the pan halfway through the bake.
One possible solution might be to use a baking stone.
This will work best if the main issue is uneven heating, which the element being covered vs uncovered might suggest. If the oven temperature itself is too low, well, it might still help but would require extensive preheating to get the stone up to temperature.
A baking stone, or clay tiles or whatever, acts as a heat sink... the stones heat up as the oven preheats (and the oven then requires more preheating as it takes a while to fill the stones with heat, often 30min extra or more) but it holds, and re-releases the heat during baking to help keep the heat even. It can serve as a buffer against heating cycles or unidirectional heat.
In your case, you would need the baking stone to be underneath your lasagne. Since you started with comparing it to double-exposed-element ovens, it would be the most similar if the stone could be held underneath the rack you're cooking the lasagne on... on the next rack down or even on he bottom of your oven, depending on the oven's layout and construction.
Direct contact will allow heat to transfer more rapidly and can have other effects on food being cooked - like much shorter cooking times, more browning (or scorching) on the bottom, etc - which can be good for some uses, and not so good for others. I tend to use direct contact a lot more, but it's a personal preference.