This time last year we had the same issue. Cold snap, time to turn on the heat! But oh no - nothing happens! We haven't run the unit for a while, enjoying the fresh air with open windows. I move the switch to heat and bump up the thermostat and - nothing. Last year we called our gas company, thinking they might be able to help. Someone there gave me a thermostat trick that worked, and now I do not remember what it was! It was basically to turn the thermostat all the way down on cool and let it run, then turn it off or switch it to heat... the details are fuzzy and what I am trying isn't working. Help! The thermostat is a Dico, if that matters. Thanks!

What brand furnace do you have? Does it vent with plastic or metal pipe?

High Efficiency Compaq 10 is what it says on the unit. I actually just stepped outside and noticed it is running, so I came inside and switched the thermostat to "on" instead of "auto". I have no idea whether pipe is plastic or metal. Landlord just said when we moved in last year "brand new heat pump". Vents in the floor... I'm sorry, this is not my field so I'm not sure what info to give you that will help. Thanks!