Consumer Reports carried an interesting story today about how
lining your oven can void the warranty.
From the article,
Lining the oven bottom with foil can void your warranty if the manufacturer advises against it in the manual or has stamped the warning on the oven cavity. This applies to gas and electric ranges. So even though reading the owner’s manual can be a snooze, we recommend it.
It is important to recognize how a seemingly simple approach to save a few minutes cleaning up after baking can have significant long term impact on the warranty coverage of your costly appliances. Most modern ovens have ‘self-cleaning’ features that eliminate the need to provide your own method for reducing the cleanup effort.
If you are baking something that you are concerned may spill over, Consumer Reports suggests putting a baking sheet on the rack under your baked item.