i'm having a problem with my furnace, the unit comes on and blows cold air. it has done this 2 nights this week. on wednesday AM i just went downstairs opened the top cover, turned off the emergency switch and turned it on and it began to work. i still had a technician come over and take a look and he said it all checked out OK, he looked at the thermostat and found some loose wires and blamed it on that. (I was skeptical.) sure enough Thursday night same thing happened. before resetting it via the emergency switch i opened up top and bottom panels so i could watch the board to look for a error code. i pressed the switch for the lower panel, the unit little fan came on and the ignitor started getting red, the flames came on the big fan came on. The flames turned off and the ignitor came back on and the flames turned on. the flames went out again and the ignitor again came back on. the flames came on again, then the flames went out again and the unit turned itself off. the red light on the control board flashed 7 times in 3 seconds and it kept flashing this sequence until turned it off at the emergency switch. does any know what the 7 flashes mean on this furnace?