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Symptom Possible Cause Corrective Action
No Heat/No Cool/No Fan
(common problems)
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.
4. Loose connection to thermostat or system.
Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety inter-
lock or door switch.
Tighten connections.
No Heat 1. Pilot light not lit.
2. Furnace Lock-Out Condition. Heat
may also be intermittent.
3. Heating system requires service or
thermostat requires replacement.
Re-light pilot.
Many furnaces have safety devices that shut down when
a lock-out condition occurs. If the heat works intermittently
contact the furnace manufacturer or local HVAC service
person for assistance.
Diagnostic: Set SYSTEM Switch to HEAT and raise the
setpoint above room temperature. Within a few seconds the
thermostat should make a soft click sound. This sound usu-
ally indicates the thermostat is operating properly. If the ther-
mostat 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, contact the furnace
manufacturer or a HVAC service person to verify the heating
is operating correctly.
No Cool 1. Cooling system requires service or
thermostat requires replacement.
Same 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 fi ve minute delay before
the thermostat clicks in Cooling.
Heat, Cool or Fan
Runs Constantly
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.
Check each wire connection to verify they are not shorted or
touching together. No bare wire should stick out from under
terminal block. Try resetting the thermostat as described
above. 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 oper-
ates correctly, replace the thermostat.
Thermostat Setting &
Thermostat Thermometer
Disagree
1. Thermostat thermometer setting
requires adjustment.
The thermometer can be adjusted +/- 4 degrees. See
Temperature Display Adjustment in the Confi guration Menu
section.
Furnace (Air Conditioner)
Cycles Too Fast or Too
Slow (narrow or wide
temperature swing)
1. The location of the thermostat and/or
the size of the Heating System may
be infl uencing the cycle rate.
Digital thermostats provide precise control and cycle faster
than older mechanical models. The system turns on and off
more frequently but runs for a shorter time so there is no
increase in energy use. If you would like an increased cycle
time, choose SL for slow cycle in the Confi guration menu,
step 6 (heat), 7 (cool) or 8 (heat pump). If an acceptable
cycle rate is not achieved, contact a local HVAC service
person for additional suggestions.
TROUBLESHOOTING
Reset Operation
Note: When thermostat is reset, installer confi guration menu settings and programming will reset to factory settings.
If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation, you can reset the thermostat by removing
the wires from terminals R and C (do not short them together) and removing batteries for 2 minutes. After resetting the thermostat, replace the
wires and batteries. If the thermostat has been reset and still does not function correctly contact your heating/cooling service person or place
of purchase.
Note: Be sure to review the installer confi guration menu settings.
To reset the programming, clock and confi guration settings, press
and and the FAN button simultaneously. The thermostat should
go blank and then all segments will be displayed momentarily.
www.white-rodgers.com
HOMEOWNER HELP LINE: 1-800-284-2925
White-Rodgers is a division
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark
of Emerson Electric Co.