15
Troubleshooting
If you have difficulty with your thermostat, please try the following suggestions.
Most problems can be corrected quickly and easily.
Display is blank
• Make sure fresh AA alkaline batteries are correctly installed
Temperature
settings do not
change
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).
Cannot change
system setting to
Cool
• Check Function 1: System Type to make sure it is set to match your heating
and cooling equipment
Fan does not turn
on when heat is
required
• Check Function 3: Heating Fan Control to make sure it is set to match your
heating equipment
Heating or cooling
system does not
respond
• Press
SYSTEM
button to set system to Heat. Make sure the temperature is
set higher than the Inside temperature.
• Press
SYSTEM
button to set system to Cool. Make sure the temperature is
set lower than the Inside temperature.
• Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Wait 5 minutes for the system to respond.
“Cool On” or
“Heat On” is
flashing
• Compressor protection feature is engaged. Wait 5 minutes for the system to
restart safely, without damage to the compressor.
Heat pump issues
cool air in heat
mode, or warm air
in cool mode
• Check Function 2: Heat Pump Changeover Valve to make sure it is properly
configured for your system
Heating and
cooling equipment
running at the
same time (or heat
does not turn off)
• Check Function 1: System Type to make sure it is set to match your heating
and cooling equipment.
• Grasp and pull thermostat away from wallplate. Check to make sure bare
wires are not touching each other.
Heating system
is running in cool
mode
• Check Function 1: System Type to make sure it is set to match your heating
and cooling equipment
For assistance with this product, please visit http://yourhome.honeywell.com or
call Honeywell Customer Care toll-free at 1-800-468-1502.
