Here are things to check to see if you oven is clean:
1. The door: Can you see into the oven when you switch on the oven light? Are there any drips apparent on the door? So is is the door clean on both sides?
2. The control knobs: Are the control knobs brown in colour and or sticky to the touch?
3. The inside of the oven: Are there any bits of burnt on carbon on the inside of the oven? Burnt on carbon is the black bits which you probably can't remove? If you have a dog or cat are there any cats hairs inside your oven either on the door or on the floor of the oven. Is the top of the oven around the grill greasy or black with burnt on carbon? Are the racks brown or black and are they greasy? Is the grill pan either black and/or greasy? If you can see the bulb cover is it clear? Does the inside fill greasy to the touch?
4. The outside of the oven: is the stainless steel spotless and shining? Are there any marks of grease on the outside at all?
5. The hob: Does the hob pot stand racks have black bits on it? Is it dull or greasy? If the hob is a ceramic one are there any marks on it at all?
6. Is your extractor or extractor hood greasy?If it has filter paper in it has it gone red or is it brown? If it has aluminium filters are they discoloured in any way?
Of course once we have cleaned your oven professionally everything will be clean and sparkling with the "new" look and feel.