Troubleshooting - White Rodgers M100 Installation Instructions Manual

8

TROUBLESHOOTING

Symptom
No Heat/No Cool/No Fan
(common problems)
No Heat
Intermittent Heat
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
Adjusting Thermometer
White-Rodgers is a division
of Emerson Electric Co.
Possible Cause
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.
1. Pilot light not lit.
2. Broken or melted anticipator wire.
3. Loose connection to thermostat or
system.
4. Thermostat or heating system re-
quires replacement or service.
5. System Switch not set to Heat.
1. Furnace Lock-Out Condition
1. Loose connection to thermostat or
system.
2. Thermostat or cooling system
requires
3. System Switch not set to Cool.
1. Possible short in wiring.
2. Possible short in thermostat.
3. Possible short in heat/cool/fan
system.
See Step 5, Adjusting the Anticipator.
1. Poor thermostat location for sensing
room temperature.
2. Cooling system over or undersized.
3. Excessive Current draw influencing
thermostat.
1. Thermostat thermometer setting
requires adjustment.
2. Thermostat setting lever requires
calibration.
1. Thermostat thermometer disagrees
with other room thermometers.
www.white-rodgers.com
Corrective Action
Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety
interlock or door switch.
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 at-
tached.
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.
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.
Verify thermostat and system wires are securely at-
tached.
Your cooling system manufacturer or service replace-
ment 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 cool-
ing condition persists, replace the thermostat.
Set System Switch to Cool and lower temp below room
temp.
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.
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.
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.
The thermometer can be adjusted by using a standard
slotted screwdriver. Turn the thermom-eter pointer
screw located inside the front cover
to change the setting. For calibrating the setting lever
contact a local heating and cooling service person.
The thermometer on the thermostat is accurately
calibrated at our factory but you can adjusted it by using
a standard slotted screwdriver. Turn the thermometer
pointer screw located inside the front cover to change
the setting.