When putting the thermostat on COOL and adjusting the desired temperature below the room temperature, OVERRIDE appears above the current temperature.

My guess based on other thermostats is that there is a program that sets the temperature based on the time-of-day. If you manually override the programmed setting it will give this indication. At the next programmed time setting, the temperature setting will revert to the programmed temperature and the override indication will go away.

There should be some way to step through the program to see what the time/temperature settings are and adjust them to your liking. The manual should describe this in detail.

Hope this helps,
WallyH

I have to agree with wally, read your user manual and it explains how to override the preset factory default settings and put in your own.

If you don't have one,you can download it here,

NOMA THERMOSTAT 52-2557-0 Manuals (http://www.manualsdrive.com/results.php?lang=en&search=NOMA%20THERMOSTAT%2052-2557-0#.V7B_ypgrKCg)