My oven was working properly until I cleaned it recently. I always use an oven thermometer to make sure that the temperature is close to the temperature set on the dial. My first problem, after cleaning, the temperature showing on the thermometer is much higher than my my oven is set at, for example the oven is set for 350 and the oven thermometer shows 400.

I know that the standard store bought oven thermometer isn't a exact measure of the true temperature, but prior to cleaning the oven temperature shown on the thermometer and the actual oven setting were always pretty close.

I set the oven to a lower temperature so that the temperature shown on the oven thermometer was at the temperature I required for baking. This brings me to my next problem, the bottoms of everything I bake is getting incinerated.

What could I have possibly done when I was cleaning the oven to create this mess and how do I fix it!

Any help would be appreciated