thermostat setting will move up to 80 or 90 dgrees at random. White rogers f86-344

There is no such thermostat number for white rodgers.
BUT
There is a 1f86-344 so I figure that must be it.
Give this a try

Reset Operation

If a voltage spike or static discharge blanks out the display or
Causes erratic thermostat operation you can reset the thermostat
By pressing , and move the SYSTEM switch from
OFF to HEAT at the same time. This also resets the factory
Defaults to the configuration menu. If the thermostat has
Power, has been reset and still does not function correctly
Contact your heating/cooling service person or place of purchase

See pictures and a complete book for your thermostat below.

http://www.white-rodgers.com/wrdhom/.../0037-6585.pdf