Troubleshooting - White Rodgers 1F78 Installation Instructions Manual

8

TROUBLESHOOTING

CONTINUED FROM SIXTH PAGE
Symptom
No Heat (continued)
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
Thermostat Thermometer
Disagree
Thermostat Does Not
Follow Program
Blank Display and/or
Keypad Not Responding
Possible Cause
5. Heating system requires service or
raise 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
infl uencing the cycle rate.
1. The location of the thermostat and the size
of the Cooling System can infl uence the
cycle rate.
1. Thermostat thermometer setting requires
adjustment.
1. AM or PM set incorrectly in program.
2. AM or PM set incorrectly on the clock.
3. Voltage spike or static discharge.
1. Voltage spike or static discharge.
2. Battery change required.
www.white-rodgers.com
Corrective Action
Diagnostic: Set SYSTEM Switch to HEAT and
the setpoint above room temperature. Within a few
seconds the thermostat should make a soft click
sound. This sound usually indicates the thermo-
stat 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, contact the furnace manufacturer or a
service person to verify the heating is operating
correctly.
Set SYSTEM Switch to COOL and lower setpoint
temperature 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 fi ve minute delay before the
thermostat clicks in Cooling.
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 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 operates correctly, replace the thermostat.
Digital thermostats normally provide precise
temperature control and may cycle faster than
some older mechanical models. A faster cycle
rate means the unit turns on and off more
frequently but runs for a shorter time so there is
no increase in energy use. If you would like to
increase the cycle time, clip Jumper W-905 as
mentioned in the instructions for Hydronic Heating
Systems. It is not possible to shorten the cycle
time. If an acceptable cycle rate is not achieved as
received or by clipping W-905 contact a local
service person for additional suggestions.
The cycle rate for cooling is fi xed and can not
be adjusted. Contact a local service person for
suggestions.
The thermometer can be adjusted +/- 3 degrees.
See Temperature Display Adjustment in the
Operation section.
Check current clock and program settings
including the AM or PM designations for each
time period. If a voltage spike or a static discharge
occurs use the Reset Operation listed above.
Replace batteries and check heat/cool
system for proper operation. If a voltage spike occurs
use the Reset Operation listed above.