30 • Commercial Communicating Programmable Thermostat I&O Manual
026-1729 Rev 2 15-NOV-2016
No Cool
No Heat or No Cool
Heat, Cool, or Fan Runs Constantly
Blank Display and/or Keypad Not Responding
Possible Cause
Corrective Action
System Switch not set to COOL.
Press the
SYSTEM
button to select COOL and press
to lower the
temperature setpoint below room temperature.
Loose connection to thermostat or system.
Verify thermostat and system wires are securely attached.
Heating system requires service or
thermostat requires replacement.
Diagnostic: Press the
SYSTEM
button to select COOL and press
to
lower the temperature setpoint below 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 described on
Section 10.1.,
Reset
Operation
. If the thermostat does not click after being reset, contact your
HVAC contractor or place of purchase for a replacement. If the
thermostat clicks, contact the furnace manufacturer or HVAC contractor
to verify the heating is operating correctly.
Table 10-3
- No Cool
Possible Cause
Corrective Action
Thermostat may be in Load Shed (a Control
Event is in progress).
Wait for the Control Event to end.
Table 10-4
- No Heat or No Cool
Possible Cause
Corrective Action
Fan set to ON.
Change Fan to AUTO.
Possible short in wiring, thermostat, or
HVAC 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 as described on
Section 10.1.,
Reset Operation
.
If the condition persists, the manufacturer of your system or HVAC
contractor can instruct you on how to test the HVAC system for correct
operation. If the system operates correctly, replace the thermostat.
Table 10-5
- Heat, Cool, or Fan Runs Constantly
Possible Cause
Corrective Action
Voltage spike or static discharge.
Use the Reset Operation described on
Section 10.1.,
Reset Operation
.
Table 10-6
- Blank Display and/or Keypad Not Responding