I have a whirlpool accubake gas oven converted to propane. When I turn the oven on the readout acts like it is preheating but the oven never comes on. I hear one click but that's all. I took the bottom out and looked at the igniter and it does not turn red, but I'm not sure it is supposed to. I am not sure if it is the igniter or the safety valve. How do I know for sure if I don't have a meter