My range CVG4280 B has four burners. The knob controlling the rear left is very difficult to turn but in any event does not ignite (though I can smell gas when I sort of force it on). The front left burner knob turns but nothing happens (i.e. does not create a flame). When I left one of the faulty burners in the "on" position for 15 seconds I could smell gas and finally saw a hint of a flame coming from somewhere other than the burner itself. The other two burners on the range work just fine.