I am renting a property that has an old Indesit electric oven. I have no idea of the model & there is no manual for it. It has 2 knobs on the front. 1 for the temperature & 1 that has just got numbers 1 to 4 on it. I can't tell when the oven or grill is on with it being an old model the paint has worn away to tell you what each number is for! Any help out there?