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18-HD82D1-1B-EN
Troubleshooting
Troubleshooting
Symptom Possible Cause Action
Display will not come on Loss of 24VAC between R & C at the Control 1) Check wiring between R & C
2) Check transformer for 24VAC output
3) Check for broken or shorted thermostat wire
Indoor Temperature
display is incorrect
1) Indoor temperature display needs calibrating
(always allow 1 hour before calibrating after
any power cycle)
2) Heat from the touchscreen is being trapped
within the body of the control
1) Calibrate indoor temperature sensor
2) Relocate the control away from any competing air sources
or redirect the air sources away from the control
Indoor humidity display is
incorrect
Indoor humidity sensor needs calibrating Calibrate humidity sensor
Room temperature
overshoots the desired
setpoint in cooling mode
1) The delta “Off” in cooling mode is set to a
negative number
2) Cooling overshoot is enabled and the indoor
RH is higher than the target cooling RH
3) Minimum compressor on time has not
been met
1) Intended operation; if objectionable, change the delta “Off”
to 0 degrees
2) Intended operation: if objectionable, disable cooling over-
shoot or raise cooling target RH
3) Intended operation; if objectionable, change Control
Response settings in the Installers Settings, Comfort Settings
Menu
Room temperature
overshoots the desired
setpoint in heating mode
Minimum compressor/indoor heat on time has
not been met
Intended operation; if objectionable, change control response
settings in the Installers Settings, Comfort Settings Menu
Cooling will not come on 1) System mode is not set to Cool/Auto or
setpoint is set too high
2) Delta “On” for cooling is set too high
3) Minimum off time delay is being enforced
4) Cooling system may need service
1) Select the correct system mode and/or lower the setpoint
2) Change the delta “On” setting for cooling mode
3) Intended operation; if objectionable, change Control
Response settings in the Installers Settings, Comfort Settings
Menu
4) Check/repair system
Heating will not come on 1) System mode is not set to Heat/Auto or
setpoint is set too low
2) Delta “On” for heating is set too high
3) Minimum off time delay is being enforced
4) Heating system may need service
1) Select the correct system mode and/or raise the setpoint
2) Change the delta “On” setting for heating mode
3) Intended operation; if objectionable, change Control
Response settings in the Installers Settings, Comfort Settings
Menu
4) Check/repair system
Heating or Cooling is
being displayed, but no
air coming from registers/
vents
1) Fan delay time has not expired
2) System is not operating properly
1) Wait one minute for blower delay to end, then recheck
register/grills
2) Check/repair system
Fan runs all the time 1) Fan mode is set to “On” or “Circ”
2) System is not operating properly
1) Intended operation; if objectionable, change fan mode to “Auto”
2) Check/repair system
Fan is set to “On” but not
running
1) Smart continuous fan (SCF) is enabled and
the indoor humidity is higher than the cooling
target RH (SCF will be displayed on fan mode
button)
2) System is not operating properly
1) Intended operation; if objectionable, disable SCF or raise
cooling target humidity
2) Check/repair system
XR724 INSTALLER’S GUIDE
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