At location manager stated that oven works but valve knob will not turn. I found knob seized up I lubricated but it still will not turn I will order parts and return to make repairs. 07/29/2019 At location with follow up part for oven. I turned gas off and removed oven knobs 2 of the knobs were stuck on and broke tips off valve. I then replaced bad oven valve and tested unit working well.