Home Heat and air blowing cold air on heating setting plenty of propane.?

Hi,I would check to see if you have a flame. No flame COLD AIR.Some thing in controls will hot ignite your pilot light.your blower should not operate till it senses the heat of flame.Also your ignitor tip may be bad,may look red hot ,but not enough to ignite gas.Be safe, call furnace repairman.Good Luck.