TROUBLESHOOTING
8
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.
Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety
interlock or door switch.
No Heat
1. Pilot light not lit.
2. Broken or melted anticipator wire.
3. Loose connection to thermostat or system.
4. Thermostat or heating system requires
replacement or service.
5. System Switch not set to Heat.
Re-light pilot.
Excessive current or dead short in system. Have a
qualified service person check the system before
replacing thermostat.
Verify thermostat and system wires are securely
attached.
Your furnace manufacturer or service person can
describe how to test the heating system to verify it is
operating correctly. If the heating system is capable of
operation and the no heat condition persists, replace the
thermostat.
Set System Switch to Heat and raise temp above room
temp.
Intermittent Heat
1. Furnace Lock-Out Condition
Many furnaces have safety devices that shut the system
down when a lock-out condition occurs. If the heat
works intermittently contact the furnace manufacturer or
local service person for assistance.
No Cool
1. Loose connection to thermostat or system.
2. Thermostat or cooling system requires
replacement or service.
3. System Switch not set to Cool.
Verify thermostat and system wires are securely
attached.
Your cooling system manufacturer or service person
can describe how to test the cooling system to verify it
is operating correctly. If the cooling system is capable of
operation and the no cooling condition persists, replace
the thermostat.
Set System Switch to Cool and lower temp below room
temp.
Heat, Cool or Fan Runs
Constantly
1. Possible short in wiring.
2. Possible short in thermostat
3. Possible short in heat/cool/fan system.
Check each wire connection to the thermostat to verify
it is neatly looped under the terminals. No extra wire
should stick out from under the terminals.
Furnace Cycles Too Fast or
Too Slow Narrow or wide
temperature swing
See Step 5, Adjusting the Anticipator.
The anticipation setting is the only adjustment that
effects the heating cycle rate. If an acceptable cycle
rate is not achieved using the anticipator contact a local
service person for additional suggestions. The location
of the thermostat, size of the Heat/Cool System and
current draw can influence the cycle rate.
Cooling Cycles Too Fast or
Too Slow (narrow or wide
temperature swing)
1. Poor thermostat location for sensing room
temperature.
2. Cooling system over or undersized.
3. Excessive Current draw influencing thermostat.
The cycle rate for cooling can not be adjusted. The
location of the thermostat, size of the Cool system and
current draw can influence the cycle rate. Contact a local
service person for suggestions.
Thermostat Setting and
Thermostat Thermometer
Disagree
1. Thermostat thermometer setting requires
adjustment.
2. Thermostat setting lever requires calibration.
The thermometer can be adjusted by using a standard
slotted screwdriver. Turn the thermometer pointer screw
located inside the front cover to change the setting. For
calibrating the setting lever contact a local heating and
cooling service person.
Adjusting Thermometer
1. Thermostat thermometer disagrees with other
room thermometers.
The thermometer on the thermostat is accurately
calibrated at our factory but you can adjust it by using
a standard slotted screwdriver. Turn the thermometer
pointer screw located inside the front cover to change
the setting.
White-Rodgers is a business
of Emerson Electric Co.
The Emerson logo is a
trademark and service mark
of Emerson Electric Co.
white-rodgers.com
emersonclimate.com
