White Rodgers 875 Thermostat User Manual


 
Symptom Possible Cause Corrective Action
No Cool 1. SYSTEM Switch not set to COOL Set SYSTEM Switch to COOL and lower setpoint
below room temperature.
2. Loose connection to thermostat or system. Verify thermostat and system wires are securely
attached.
3. Cooling System requires service or thermostat Same procedure as diagnostic for No Heat
requires replacement. 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 if the compressor
lock-out option is selected in the confi guration
menu (Item 6).
Heat, Cool or Fan Runs Constantly. 1. FAN Switch set to Fan ON. Check each wire connection to verify they are
2. Possible short in wiring. not shorted or touching together. No bare wire
3. Possible short in thermostat. should stick out from under terminal screws.
4. Possible short in Heat/Cool/Fan system. Try resetting the thermostat. 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.
Furnace Cycles Too Fast or Too Slow 1. The location of the thermostat and/or the size Item 2 in the Confi guration Menu is the adjustment
(narrow or wide temperature swing) of the Heating System may be infl uencing the that controls the cycle rate. If an acceptable cycle
cycle rate. rate is not achieved using the FA (Fast) or SL
(Slow) adjustment contact a local service person
for additional suggestions.
Cooling Cycles Too Fast or Too Slow 1. The location of the thermostat and/or the size The cycle rate for cooling is fi xed and can not be
(narrow or wide temperature swing) of the Cooling System may be infl uencing the adjusted. Contact a local service person for
cycle rate. suggestions.
Thermostat Setting and Thermometer 1. Thermostat thermometer setting requires The thermometer can be adjusted +/- 4 degrees as
Disagree adjustment. listed in item 7 of the Confi guration Menu. No other
adjustment is possible.
Clock Loses or Gains Time 1. Loss of power to thermostat and low batteries. The thermostat will maintain its program in memory
even with no power/no batteries but the clock time
will be incorrect when power is restored. See No
Heat/No Cool/No Fan (common problems) above
for items to check in the system.
Heat or Cool Starts Early 1. EMR activated See Confi guration Menu (Item 4).
Thermostat Does Not Follow Program 1. AM or PM set incorrectly in program. Check current clock and program settings including
2. AM or PM set incorrectly on the clock. the AM or PM designations for each time period.
3. Voltage spike or static discharge. If a voltage spike or static discharge occurs use the
Reset Operation listed above.
Blank Display and/or Keypad Not 1. Loss of power and dead batteries. Replace batteries and check heat/cool system for
Responding 2. Voltage Spike or Static Discharge. proper operation. If a voltage spike or static
discharge occurs use the Reset Operation
listed above.
TROUBLESHOOTING
www.white-rodgers.com
St. Louis, Missouri Markham, Ontario
White-Rodgers is a division
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark
of Emerson Electric Co.
HOMEOWNER HELP LINE: 1-800-284-2925