[h1]Luxaire Furnace Model PCUHBLD12N100C[/h1]The furnace starts properly, ignites, gas valve opens, and it works for 4 seconds. Then the flame turns off. The indicator light is slow blinking amber, showing a normal operation with a call for heat. I already replaced the flame sensor with a new one. Nothing has changed. At the end of last winter, I replaced the limit switch because I was getting a code (4 blinks as I recall). There was a problem then but the weather got warm and I forgot about the problem. The furnace would work properly for a while, and then it would blow cold air. If I turned it off then on, it would blow warm again. Since I could access the power to it easily, I ignored the problem. Now, it seems something else is going on. This video [url]https://www.youtube.com/watch?v=b0sAGt-1niU&vl=en[/url] only gives one possible problem if it fails after ignition, the flame sensor. I'm thinking maybe the blower fan motor is dead. I didn't check if it was running. Maybe that's the problem. I would appreciate any suggestions.

where is the actuator andwhat is it's function? Thanks