Furnace Repairs

When the weather turned colder after our few days of warm weather, I noticed that it was getting chilly in the house. So, after putting on a sweatshirt and still feeling chilled I decided it was time to turn the furnace on. Off I went to flip the switch on the thermostat. I flipped it, and....nothing happened. Well, that's not necessarily unusual, Hubster says I must have a loose wire (guess it's better than a loose screw) so I waited a few minutes and tried again. Nothing, nada, zilch. Temp is now 63 degrees in the house. I tried every trick I could think of to make it work. Went downstairs to the basement and turned the furnace off and on, took out the batteries from the thermostat and replaced them, etc. etc. Still nothing.
So, about 3 hours later, after I finished muttering just a few choice words and lamenting the fact that the furnace people were here not 2 weeks ago and didn't it figure that it worked then but now, nothing, I thought I'd look one last time at the thermostat and hope for some divine revelation on how to repair it without costing an arm and a leg.
And, I found out something.
The furnace works really well when you turn it to "heat" and not "cool".