In Case Of Difficulty - Honeywell RTH6400 Operating Manual

Operating Manual

In case of difficulty

If you have difficulty with your thermostat, please try the following suggestions.
Most problems can be corrected quickly and easily.
Display is blank
Temperature
Make sure heating and cooling temperatures are set to acceptable ranges:
settings do not
change
69-2211EF—05
• Make sure fresh AA alkaline batteries are correctly installed
(see page 15).
• Heat: 40° to 90°F (4.5° to 32°C).
• Cool: 50° to 99°F (10° to 37°C).
20