Old Westinghouse convention oven range E242N1W3 - the start and stop clock timers are preventing my turning on oven and I don't know what I did or how to fix the problem - in other words, how do the timer controls work on this (or any other model with manual timers - i.e. you turn a nob.) There is no 'off' only the same numbers as a clock (12, 3, 6 and 9)