How to inspect a used comm. convection oven?

I would be surprised if it is mold. Is it in a very humid climate? Most doors can be taken apart and you MIGHT be able to clean the glass. However, be aware that some ovens use a reflective coating on the glass and cleaning might ruin it. Check with the manufacturer or a local repair center.

Just the usual: is it a reputable - reliable brand/model, how old is it, why is it for sale, do the controls work, is the temperature accurate, is there any visible corrosion/buckling in bottom or side panels, are the gaskets in good shape, does the convection fan work, do both heating elements/burners work, if gas does the automatic ignition work? Too many variables to give a definitive answer. It would have to be a darned good buy to take any chances.

Raj

Thanks for the answers. It is a reputable brand (Southbend). I am in New Orleans, LA, so it is also a very humid climate. I will certainly use the checkpoint list you gave me as starters. Thanks for the info, I appreciate it.