This is a brand new 96% variable speed gas furnace on a new build home now coming on almost 2yrs. The furnace has "quit" heating 3x in the last 2 months smack in the middle of a MN winter. I managed to cycle the 3 thermostats in 3 zones and somehow got it to ignite the first 2 times. This time, it was not going to happen. Still just showed the erratic small green light to the left of the flashing red one. Frustrated from having to run up and down stairs more than 5x in the middle of the night, I guess I thought I'd pop off the bottom panel. As soon as the left side loosened and popped open (but not the right side yet) I heard the sweet sound of the ignition clicking. I was reassured that it was working by the amber light, then the green light. So i secured the panel back in place. What might be the cause of this unpredictable behavior and failure?