Hi everyone. Strange one here. Just getting our 1999 autosleeper ready for the first trip and on trying to check the fridge operation, it appears that the gas selector knob on our Electrolux fridge has jammed. It won't push in to allow it to turn. Was fine before the winter. We assumed that these knobs came off, but this one just won't move and we don't want to damage it trying. Any advice gratefully received.