Honeywell TH2110DV PRO Operating Manual page 21

In case of difficulty
Temperature
settings do not
change
"Cool On" or
"Heat On" is
flashing
"Heat On" is not
displayed
"Cool On" is not
displayed
Make sure heating and cooling temperatures are set to acceptable
ranges:
• Heat: 40° to 90°F (4.5° to 32°C).
• Cool: 50° to 99°F (10° to 37°C).
• Compressor protection feature is engaged. Wait 5 minutes for the
system to restart safely, without damage to the compressor (see
page 14).
• Set the System switch to Heat, and set the temperature level
above the current room temperature (see page 7).
• Set the System switch to Cool, and set the temperature level
below the current room temperature (see page 7).
19 69-2799EFS—03