Installation Guide
20
18-HD98D1-1B-EN
Symptom
Possible Causes
Action
Cooling will not
come on
1. System mode is not set to Cool/
Auto or the setpoint is too high.
2. Minimum off time delay is being
enforced.
3. Cooling system may require
service.
1. Set mode to cool and lower the setpoint
below the room temperature.
2. Wait 5 minutes and recheck cooling
equipment.
3. Check/repair system.
Heating or Cooling
is displayed, but no
warm or cool air is
coming from the
registers
1. Fan delay as the heating or
cooling equipment turns on.
2. Equipment is not working
properly.
1. Wait a minute for blower delays and
recheck registers.
2. Check/repair system.
Fan runs all the time
1. Fan mode is set to On,
Circulate or Clean mode.
2. There is a failure in the indoor
unit.
1. Check UX360 settings to see if fan is
set to On, Circulate or Clean mode.
2. Check indoor unit for failures (such as
tripped heating limit).
“+” symbol appears
on Home Screen
beneath Indoor
Temperature readout
Both compressor heat and
indoor heat are being called
simultaneously
No action required. Symbol is for
informational purposes only.
Fan is set to ON but
not running
1. Smart Control Fan feature has
been is engaged.
2. Blower motor is not functioning.
1. If indoor humidity is higher than desired
setpoint, the blower will cycle off with
the equipment. A humidity icon will
be displayed on the Fan Mode button
when the blower operation is being
inhibited due too high humidity.
2. Check/repair system.
Cooling or Heating
cycles too fast or too
slow (narrow or wide
temperature swings)
1. Check the location of the
UX360 for drafts.
2. Cycles per hour or aggressive
recovery is improperly set.
1. Seal air leaks behind UX360. Relocate
UX360 or apply remote indoor
temperature sensor.
2. Adjust cycle rates and aggressive
recovery features in the advanced
installer set up.
Heat pump is not
turning on; only
furnace or electric
heat strips are
running
1. Outdoor temperature is
below compressor lockout
temperature setting.
2. Compressor heating lockout
is enabled and outdoor temp
sensor is out of calibration or
failed.
3. The outdoor unit is not
reporting.
1. Adjust the compressor lockout
temperature setting if desired.
2. Check/repair outdoor sensor or wiring.
3. Check communication status of outdoor
unit.
Cannot change
system mode to
desired setting
Equipment is not configured
properly.
Check the Configuration screen to ensure
equipment is properly configured.
Screen does not
respond properly to
a button press
1. Internal UX360 hardware
failure.
2. Screen Lock has been enabled.
1. Remove UX360 from sub-base and
reset.
2. Press and hold the Menu button for 5
seconds to override screen lock.
