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Installation and User Guide
7.
Troubleshooting
Reset Operation
If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation you can reset the thermostat by
pressing
and
at the same time when system is switched from "OFF" to "HEAT" position. This also resets the factory defaults.
If the thermostat has power, has been reset and still does not function correctly contact your heating/cooling service person or place of
purchase.
Batteries
For optimum performance, we recommend replacing batteries once a year with fresh "AAA" alkaline batteries.
SYMPTOM
No Heat/No Cool/No Fan
(common problems)
No Heat
No Cool
Heat, Cool or Fan Runs Constantly.
Furnace (Air Conditioning) Cycles
Too Fast or Too Slow (narrow or
wide temperature swing)
Thermostat Setting and Thermostat
Thermometer Disagree
Blank Display and/or Keypad Not
Responding
10
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. System Switch not set to HEAT.
3. Loose connection to thermostat or system.
4. Furnace Lock-Out Condition. Heat may
also be intermittent.
5. Heating system requires service or
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 (Cooling) System may
be influencing the cycle rate.
1. Thermostat thermometer setting requires
adjustment.
1. Voltage spike or static discharge,
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.
Set System Switch to HEAT and raise setpoint above room temperature.
Verify thermostat and system wires are securely attached.
Many furnaces have safety devices that shut down when a lock-out condition
occurs. If the heat works intermittently contact the furnace manufacturer or
local service person for assistance.
Diagnostic: 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 is
operating correctly.
Set System Switch to COOL and lower setpoint
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 five 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.
Thermostat thermometer can be adjusted +/-3 degrees. See Temperature
Display Adjustment in the Operation section
Use the Reset Operation listed above.
Pub. No.
11-HD24D1-1C-EN
09/2020
Part No. 37-7792003
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