o Heat/No Cool/No Fan
1. Blown fuse or tripped circuit breaker.
2. Furnace power switch to OFF.
Replace fuse or reset breaker.
Turn switch to ON.
3. Furnace blower compartment door or
panel loose or not properly installed.
Replace door panel in proper position to engage
safety interlock or door switch.
1. Pilot light not lit.
2. SYSTEM Switch not set to HEAT.
Set SYSTEM Switch to HEAT and raise setpoint
above room temperature.
3. Loose connection to thermostat or system.
4. Furnace Lock-Out Condition. Heat may also
Verify thermostat and system wires are securelyAttached.
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.
5. Heating System requires service or
thermostat requires replacement.
Diagonistic: Set SYSTEM Switch to HEAT and raise the
setpoint above room temperature. Within a few seconds
the thermostat should make a soft click sound. This
sound usually indicates the thermostat 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 system is
1. SYSTEM Switch not set to COOL.
Set SYSTEM Switch to COOL and lower setpoint below
2. Loose connection to thermostat or system.
3. Cooling System requires service or thermostat
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 five
minute delay before the thermostat clicks in Cooling if
the compressor lock-out option is selected in the
configuration menu (Item 6).
Heat, Cool or Fan Runs Constantly
1. FAN Switch set to Fan ON.
2. Possible short in wiring.
3. Possible short in thermostat.
4. Possible short in Heat/Cool/Fan system.
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. 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
(narrow or wide temperature swing)
1. The location of the thermostat and/or the size
of the Heating System can influence the cyclerate.
Item 2 in the Configuration Menu is the adjustment
that controls the cycle rate. If an acceptable cycle
rate is not achieved using the FA (Fast) or SL
(Slow) adjustment contact a local service person for
Cooling Cycles Too Fast or Too Slow
(narrow or wide temperature swing)
1. The location of the thermostat and/or the size of the
Cooling System may be influencing thecycle rate.
The cycle rate for cooling is fixed and can not be adjusted.
Contact a local service person for suggestions.
Thermostat Setting and Thermometer
1. Thermostat thermometer setting requires
The thermometer can be adjusted +/- 4 degrees as listed
in item 7 of the Configuration Menu. No other adjustment
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
Heat or Cool Starts Early
1. EMR activated
See Configuration Menu (Item 4).
Thermostat Does Not Follow Program
1. AM or PM set incorrectly in program.
2. AM or PM set incorrectly on the clock.
3. Voltage spike or static discharge.
Check current clock and program settings including
the AM or PM designations for each time period.
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.
2. Voltage Spike or Static Discharge.
Replace batteries and check heat/cool system for
proper operation. If a voltage spike or static discharge
occurs use the Reset Operation listed above.