In Case Of Difficulty - Honeywell TH8320ZW 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
No response to
key presses (or
temperature will
not change)
Backlight is dim
Thermostat shows
the calendar
screen (year, date,
& month) when the
power is restored
69-2485EFS—05
• Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Check to make sure the thermostat is not locked (see page 17).
• 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)
• If thermostat is AC powered, a dim display is normal. The backlight
remains on at a low level, and brightens when a key is pressed.
• This indicates that the coin cell battery has drained out. Replace the
coin cell battery immediately.
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