Honeywell RTH4300B Guide D'installation page 24

Installation Guide
In case of difficulty About your new thermostat
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.
• Set the System switch to Heat, and set the temperature level above the
current room temperature.
• Set the System switch to Cool, and set the temperature level below the
current room temperature.