I have a Westinghouse gas oven model 517 Freestyle. I wondered if this oven has an oven element cover to go around the gas burner at the bottom of the oven. There seems to be a very large opening around the gas jet, this maybe why the oven does not warm up enough while cooking. Could you also tell me what the correct jet size is required for the oven running on LPG gas. If there is a cover missing am I able to purchase one from somewhere.? Thanks Vaughan.