Our gas furnace stopped working. The problem is when the thermostat calls for heat, everything looks normal from beginning: the induction fan starts to spin, then the Hot surface ignition comes on. The problem is now there is no flame comes on. It looks to me the gas valve does not open at all. The ignitor comes on for three times and stops trying. I did not see any broken wire. I don't have much experience here, so any suggestion is helpful. Thank you!