Thermostat User Manual
Operating Manual
26
69-1894EFS—03
ENGLISH
If you have difficulty with your thermostat, please try the following suggestions.  
Most problems can be corrected quickly and easily.
Display is blank 
•  Check circuit breaker and reset if necessary.
•  Make sure power switch at heating & cooling system is on.
•  Make sure furnace door is closed securely.
•  If thermostat is battery powered, make sure fresh AAA alkaline 
batteries are correctly installed (see page 20).
No response to 
key presses (or 
temperature will 
not change)
•  Check to make sure the thermostat is not locked (see page 25).
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)
Backlight is dim
•  If thermostat is battery powered, make sure fresh AAA alkaline 
batteries are correctly installed (see page 20).
•  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.
In case of difficulty










