Our thermostat went blank this afternoon and it is completely unresponsive to any button pushing. Does a Carrier programmable thermostat take batteries? If so, we've lived here 6 years and never replaced the batteries. We checked the breaker box and nothing seems to be tripped. We checked the breakers on the furnace itself. We need help! It's Saturday night, it's getting cold, and my husband and I aren't very mechanically inclined.

It is undoubtedly the batteries. Since you didn't specify which Carrier thermostat you have, I can only give you general guidance.

If there is a door, open it and see if you see any batteries. If not, you may have to pop then entire thermostat off the wall. Look around the edge of the unit and see if you can see anything that looks like a latch, and open it. If not, try prying the entire thermostat gently off the wall. It should be attached to a plastic bracket that will remain on the wall.

See the attached diagram.

Hope this helps, hope you didn't get too cold last night.
WallyH