It seems like the furnace cycles for too short of time ...can comes on then burner comes on for a minute or two then Shuts off and the fan continues to run for a minute mostly colder air....does get u...
There is a thing called a heat anticipator in your thermostat that can be adjusted to control the length of the heat periods and length of time between cycles If you can read this it tells you how to adjust it , this is probably the same stat you have ,Robertshaw , if not most stats are similar