Well, I couldn't find the "right" section that was public to ask this question so I'm asking here. I'm not 100% on the order of operations in a regular high efficiency furnace, and I was asked the question on an interview, and I'm not sure if I got it right. I know its the most basic question, so if anyone can help me out here, it'll be greatly appreciated. Basically starting at the thermostat call for heat, gas valve energizes ect, I want to make sure I know it and understand it. Thanks in advance.