24
4
TROUBLESHOOTING
®
Symptom:
Fan continues to run in cooling mode when the system has turned off.
Potential Solution:
The Residual Cooling Fan Control Feature can allow up to a 90 second fan delay after cooling
system shutdown for energy efficiency gains. The default setting is 60 seconds. This can be changed to disable this
feature or shorten the time period if desired (see section 4 of the Installer Guide).
Symptom:
Thermostat does not turn on heating or cooling system.
Potential Solution:
Check to see if
OFF
is shown in display. This indicates that the system is turned off at the
thermostat. Press the system button to select
HEAT
or
COOL
mode. After the compressor short cycle protection period
expires the system should start within several seconds.
Compressor protection features may be in effect due to compressor short cycle conditions, power outages or rolling
blackouts. See section 3.15 for full explanation of this feature.
Heat pump may be malfunctioning. Look in the lower left corner of the thermostat display. If the word
CHECK
is present,
call a professional service technician to confirm heat pump operation and provide necessary service. If heating is
required, you can press the system button to
EMER
setting, which may start the Emergency Heat source to provide
heating until the heat pump can be serviced.
Symptom:
Thermostat turns on heating instead of cooling, or cooling instead of heating.
Potential Solution:
Check thermostat wiring to make sure that the heating and cooling stages are connected to the
correct terminals on the wiring terminal block (see Installer Guide, section 6).
Symptom:
Fan runs intermittently or when system is off.
Potential Solution:
This is normal operation when fan switch is in recirculate ( ) mode.
Symptom:
System turns on prior to the end of a setback period.
Potential Solution:
Thermostat is in Adaptive Recovery Mode (see section 3.11).
Symptom:
Thermostat turns heating or cooling system on too often or not often enough.
Potential Solution:
Increase or decrease first stage temperature differential setting as appropriate to provide the
desired performance level (see section 2.4).
25
4
TROUBLESHOOTING
cont.
Symptom:
Thermostat will not follow program set points.
Potential Solutions:
Check current time of day, day of week program settings. Verify AM/PM indicator is accurately
displaying desired time settings (see section 2.1).
Check to see if
OFF
is shown in display. This indicates that the system is turned off at the thermostat. Press system
button to select
HEAT
or
COOL
mode. After the compressor short cycle protection period expires the system should
start within several seconds.
Verify your program set point time entries.
Thermostat program has been temporarily overridden. Wait until next set point and the temporary override will expire
or change set point temperature to desired comfort level.
Thermostat program is in Extended Hold (Vacation) Mode and
HOLD
is shown in display. Press
HOLD
button to release
hold and return the thermostat to normal program operation.
Symptom:
System does not automatically switch from Heating to Cooling.
Potential Solutions:
Auto Changeover was not selected or enabled during installer set-up (see section 4 of
Installation Guide and section 3.2 of this manual). Program temperature was changed due to dead band violation
(see section 3.2).
Symptom:
Thermostat turns on second or third (auxiliary) stage of heating or cooling too quickly or not quickly enough.
Potential Solution:
Increase or decrease second or third (auxiliary) stage temperature differential setting as
appropriate to provide the desired performance level (see section 2.4).
Symptom:
Low battery indicator is shown in thermostat display.
Potential Solution:
Replace back-up batteries as soon as possible (see section 3.18).
Symptom:
Fan runs constantly or for long periods of time.
Potential Solutions:
Fan control is set to ON. Fan control is set to PROG and is programmed to be on.
Symptom:
Cannot program a set point temperature lower than 45˚ F (7˚ C).
Potential Solution:
This is below the normal thermostat temperature setting range of 45˚ to 90˚ F (7˚ to 32˚ C).
