I have a Coleman Echelon 8.C model CP8C100C16MP11 and it is only putting out cold air. I checked the LEDs on the ckt bord; it shows the following: Green, steady flashing indicating normal operation. Yellow, flashing twice indicating a demand for heat. I checked the igniter and it is cold. Is there anything else I should check, & can I order a replacement part or do I have to go through a repair serviceman?