Oy and vey. When I walked by the heat register this morning it felt like cold air, which I found odd. Sometime later I walked by again and it was definitely cold air, so I called the furnace company (we're about 1 week past the warranty of course). The guy was very friendly, told me to reset the breaker and to check the filters. I noticed the high tech thermostat was flashing and it was saying "change filter" so I went and vacuumed all of the electrostatic filters (the only kind we have), and that seemed to have done the trick. But we had the condensate pump fail a couple of months ago and now this, so I am not especially thrilled with this furnace, which was VERY expensive.