Honeywell keeps calling for heat. Help!

Ok this one is KILLING me. Brand new carrier Comfort 92 furnace. Brand new home 3 months old. Set heat to 68. Furnace fires up for 4-5 minutes and gets house to 68. Not even 5 minutes later thermostat calls for heat. Blower speed has been adjusted (temp gets to around 117) and and the high limit switch is not in play. Is the Honeywell thermostat a dud? It reads 68 and still calls for heat. Thanks folks!