I have an 1F78 thermostat but it is not programmable. I have had it about 3 years. Yesterday all of a sudden a little icon appeared right below the temperature I have it set on. It looks like an asterisk. I have no idea why it is there and can't find out any information on what it is trying to tell me. My air is working but it won't and even tho it reaches the temperature that it says it is in the house, it doesn't shut off. I have to manually shut it off. Don't know what to do.