Troubleshooting - Emerson 1F85U-42NP Installation And Operating Instructions Manual

TROUBLESHOOTING

Symptom Possible Cause
1.) Blown fuse or tripped circuit
breaker
2.) Furnace power switch to OFF
No Heat/
No Cool/
3.) Furnace blower compartment
No Fan door panel loose or not properly
(common problem)
installed
4.) Loose connection to thermostat
or system
1.) System not set to Heat
2.) Loose connection to thermostat
or system
3.) Heating System requires
service or thermostat requires
replacement
No Heat
1.) System not set to Cool
2.) Loose connection to thermostat
or system
3.) Cooling System requires
service or thermostat requires
replacement
No Cool
Heat, Cool or Fan Possible short in wiring, thermostat,
Runs Constantly heat, cool or fan system
Thermostat
Display & Thermostat display requires
Thermometer adjustment
Disagree
Furnace (Air
Conditioner)
The location of the thermostat and/
Cycles Too Fast or
or the size of the Heating System
Slow (narrow or
may be influencing the cycle rate
wide temperature
swing)
(Troubleshooting continued on next page)
7
Corrective Action
1.) Replace fuse or reset breaker
2.) Turn switch to ON
3.) Replace door panel in proper position to
engage safety interlock or door switch
4.) Tighten Connections
1.) Set thermostat to Heat.
2.) Verify thermostat and system wires are
securely attached.
3.) Diagnostic: Set System to Heat and raise the
setpoint above room temperature. Within five
minutes the thermostat should make a soft click
sound and "Heat On" should appear on display.
This sound indicates the thermostat is operating
properly. If the thermostat does not click, try the
reset operation listed below. 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 system is
operating correctly.
1.) Set thermostat to Cool.
2.) Verify thermostat and system wires are securely
attached.
3.) Diagnostic: Set System to Cool and lower
setpoint below room temperature. Same
procedures 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 installer menu. (see INSTALLER
MENU, item 50)
Check each wire connection to verify they are not
shorted or touching other wires. Try resetting the
thermostat. If the condition persists contact your
HVAC service person.
Display can be adjusted +/-5°. See User Menu
item 05
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. If you would like to increase
cycle time, choose SLO for slow cycle in the
Installer menu. (Reference menu items 30, 32 &
35) If an acceptable cycle rate is not achieved,
contact your HVAC service person.
TROUBLESHOOTING (C0ntinued)
Symptom Possible Cause
1.) Heating system is not able to heat
the space to within 10 degrees of
the setpoint within 2 hours
2.) Cooling system is not able to cool
the space to within 10 degrees of
the setpoint within 2 hours
"Call for Service" 3.) If "--" is displayed for the Room
icon appears on Temperature, a replacement
displayed thermostat is needed
4.) None of the buttons operate on
the thermostat
5.) If "Call for Service" is flashing,
compressor self diagnostic is
detecting an issue with the
outdoor unit
Resetting the Thermostat or Thermostat Settings
If the thermostat has good batteries, but has a blank display or does not respond to key
presses, the thermostat should be reset by removing the batteries for 2 minutes. This reset
will not change the menu settings or program. If the condition persists after reinstalling the
batteries, replace the thermostat.
To conveniently reset only the schedule and user settings back to factory defaults, press Menu
and Backlight buttons at the same time and hold until the display goes blank and resets.
HOMEOWNER HELP LINE: 1-800-284-2925
White-Rodgers is a business
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark www.white-rodgers.com
of Emerson Electric Co. www.emersonclimate.com
Corrective Action
1.) See corrective action for "No Heat"
2.) See corrective action for "No Cool"
3.) Replace thermostat
4.) Make sure keypad lockout is not turned on ( ),
If it's OFF, try reset shown below.
5.) Contact a service person to verify the outdoor
equipment is operating correctly