I have a Trane Gas Pack model YCC024A1L0AB. The problem I have is the blower is not turning on when turning on heat. The motor works since it operates fine on the COLD setting, Auto and On. The pilot is lit as well and the burner fires up. Also notice that the fire is coming out passed the pilot light. You can turn the fan to On and then back to Auto and it will fire up and heat every time but then later we will notice the house getting cold and have to do that trick again to get it to cut on. I have replaced the sail switch and the control board was replaced about 5 years ago.