26
27
4
TROUBLESHOOTING
4
TROUBLESHOOTING
SYMPTOM
POTENTIAL SOLUTION
cont.
cont.
Symptom:
HI
is shown in the thermostat display where the room temperature is normally displayed.
Potential Solutions:
The temperature sensed by the thermostat is higher than the 99˚ F (37˚ C) upper limit of the
thermostat’s display range. The display will return to normal after the sensed temperature lowers within the 40˚ to
99˚ F (5˚ to 37˚ C) display range. Turn on the cooling system or use other methods to lower the temperature.
This condition could occur from the system being turned off during an exceptionally warm period, or upon installation
when the thermostat has been stored for a long period of time in a warm vehicle or location prior to being installed.
Symptom:
The room is too warm or too cold.
Potential Solution:
See section 3.1 of this manual to verify the current set point and make any modifications
that are necessary.
Symptom:
Thermostat display is blank.
Potential Solutions:
It is possible that AC power is not present at the thermostat and the batteries are fully
discharged. Check fuse, circuit breaker and thermostat wiring as appropriate to verify AC power is available.
Replace batteries before reprogramming thermostat. See sections 3.18 and 2.5 of this manual. If AC Power is present,
call a professional service technician to verify thermostat and system performance.
Symptom:
Cannot program a set point temperature higher than 90˚ F (32˚ C).
Potential Solution:
This is above the normal thermostat temperature setting range of 45˚ to 90˚ F (7˚ to 32˚ C).
Symptom:
Thermostat will not allow me to change the set point.
Potential Solution:
The Keypad is locked. To lock or unlock the keypad, press and hold both the and buttons at the
same time for 5 seconds. The
LOCK
segment in the display will flash as the program and temperature segments are
cleared (see section 3.10). The time segments will turn to zeros. Enter the 3 digit code programmed in section 2.4.8 of
this manual. After setting the last digit, press the
RETURN
key for 1 second. The display will return to the normal mode. If
an incorrect code is entered, the display will flash “
no
”.
Symptom:
Keypad does not function.
Potential Solution:
Keypad is locked (check for
LOCK
segment in display).
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).
