TROUBLESHOOTING
Reset Operation
If a voltage spike or static discharge blanks out the display or
causes erratic thermostat operation, you may need to reset
the thermostat. To reset, the System Switch must be in Cool,
HEAT, or EMER. Simultaneously hold the
Symptom
No Heat/No Cool/No Fan
(common problems)
No Heat
No Cool
Heat, Cool or Fan Runs
Constantly
Furnace Cycles Too Fast
or Too Slow (narrow or
wide temperature swing)
Cooling Cycles Too Fast
or Too Slow (narrow
or wide temperature
swing)
Thermostat Setting and
Thermometer Disagree
Blank Display and/or
Keypad Not Responding
Thermostat has
HP/SS switch and
Configuration Menu has
selection for HP or SS
and
buttons
Possible Cause
1. Blown fuse or tripped circuit breaker.
2. Furnace power switch to OFF.
3. Furnace blower compartment door or
panel loose or not properly installed.
1. System Switch not set to Heat.
2. Loose connection to thermostat or
system
3. Heating System requires service or
thermostat requires replacement.
1. System Switch not set to Cool.
2. Loose connection to thermostat or
system.
3. Cooling System requires service or
thermostat requires replacement
1. Possible short in wiring.
2. Possible short in thermostat.
3. Possible short in Heat/Cool/Fan
system.
4. Fan Switch set to Fan On.
1. The location of the thermostat and/or
the size of the Heating System may be
influencing the cycle rate.
1. The location of the thermostat and/or
the size of the Cooling System may
be influencing the cycle rate.
1. Thermostat thermometer setting
requires adjustment.
1. Voltage Spike or Static Discharge.
1. Earlier version of thermostat model.
for approximately 10 seconds until the display goes blank. If
the thermostat has power, has been reset and still does not
function correctly contact your heating/cooling service person
or place of purchase.
Corrective Action
Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety
interlock or door switch.
Set System Switch to Heat and raise setpoint above room
temperature.
Verify thermostat and system wires are securely attached.
Diagnostic: Set System Switch to Heat and raise the
setpoint above room temperature. Within a five minutes
the thermostat should make a soft click sound. This sound
usually indicates the thermostat is operating properly. If
the thermostat does not click, try the reset operation listed
above. If the thermostat does not click after being reset
contact your heating and cooling service person or place of
purchase for a replacement. If the thermostat clicks, con-
tact the furnace manufacturer or a service person to verify
the heating system is operating correctly.
Set System Switch to Cool and lower setpoint below room
temperature.
Verify thermostat and system wires are securely attached.
Same procedure as diagnostic for No Heat condition
except set the thermostat to Cool and lower the setpoint
below the room temperature. There may be up to a five
minute delay before the thermostat clicks in Cooling if the
compressor lock-out option is selected in the configuration
menu (Item 4).
Check each wire connection to verify they are not shorted
or touching together. No bare wire should stick out from
under terminal screws. Try resetting the thermostat as
described below. If the condition persists, the manufacturer
of your system or service person can instruct you on how
to test the Heat/Cool system for correct operation. If the
system operates correctly, replace the thermostat.
Item 2 in the Configuration Menu is the adjustment that
controls the cycle rate. If an acceptable cycle rate is not
achieved using the FA (Fast) or SL (Slow) adjustment con-
tact a local service person for additional suggestions.
The cycle rate for cooling is fixed and can not be adjusted.
Contact a local service person for suggestions.
The thermometer can be adjusted +/- 4 degrees as listed
in item 5 of the Configuration Menu. No other adjustment is
possible.
If a voltage spike or static discharge occurs use the Reset
Operation listed above.
If switch is present, it must be in HP position for proper fan
operation. If selection appears in Configuration Menu, it
must be set for HP.
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