I have an 1F80-261 White-Rogers programmable thermostat that is running at least TEN degrees hotter than what it is set at.
Is it time for a new one? The manual only allows for 4 degrees up or down to "adjust" and that did nothing. I am setting it at 47 degrees at night. Feels odd to do that!
Thanks.

This is just a thought since I never had a White Rodgers thermostat do that. Your thermostat display can be set to display temperature in Fahrenheit or Celsius. Refer to your instructions under Installation/Configuration Menu.
Have you checked that?

Here is the factory manual if you do not have one.

http://www.white-rodgers.com/wrdhom/.../0037-6288.pdf

HVAC1000,
Yes, I checked the manual and settings. I have the thermostat set to Fahrenheit. Very strange indeed.

A failing temperature sensor will produce this effect. Look for a small "reset" button and press it (if present). If not, try this: turn off power to the system and remove thermostat batteries (if present). Wait about an hour, then re-install. If it starts working correctly, you may have experienced a static-induced "glitch". If not, you should probably replace that thermostat gone crazy... before it starts pulling its shirt up and yelling "WOOOOOO!":p

Well... so much for a re-boot. My trusty White-Rogers is headed for the scrap heap and I am getting a new NON programmable simple to use, good old fashioned Honeywell with a dial. No buttons, no smoke and mirrors.
Thanks SO much for the help and suggestions. It was worth a try.