Trane 18-HD64D1-1 User Manual

18-HD64D1-1 

 

    17 

Thermostat displays an alert 
code on the screen.

Alert Code is present.

Refer to the Alert Code Addendum.  Check the 
Alert icons in the diagnostic screen.

Display will not come on

Loss of 24VAC between R & B at the thermo-
stat.

1) Check wiring between R & B to see if R & D, or 
B & D have been reversed.
2) Check transformer for 24VAC output.
3) Check for broken or shorted thermostat wire.

Indoor temperature display is 
incorrect.

Indoor temperature display needs calibration.

Calibrate temperature sensor from thermostat 
menu.

Indoor humidity display is incor-
rect.

Indoor humidity display needs calibration.

Calibrate humidity sensor from the thermostat 
menu.

Room temperature overshoots 
when the Heat/Cool setting is 
changed more than 2°.

1) Oversized heating/cooling equipment under 
current conditions.  Control cannot respond fast 
enough to prevent overshooting.
2) Improper location of thermostat.
3) Aggressive recovery is activated.

1) Compare heat load calculation to equipment 
chosen.
2) Relocate thermostat (or use remote sensor) if 
thermostat is in “dead” spot (poor or no air circula-
tion).  
3) Deactivate aggressive recovery.

Heating will not come on.

1) System mode is not set to heat/Auto or set-
point is set too low.
2) Minimum off time delay is being enforced.
3) Heating system may require service.

1) Set mode to heat and raise the setpoint above 
the room temperature.
2) Wait for 5 minutes and recheck heating equip-
ment.
3) Check/repair system.

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 for 5 minutes and recheck cooling equip-
ment.
3) Check/repair system.

Heating or Cooling is displayed, 
but no warm or cool air is coming 
from the registers.

1) There is a 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 thermostat settings to see if fan is set to 
On, Circulate or Clean mode.
2) Check indoor unit for failures (such as tripped 
heating limit).

Fan is set to ON but not running.

1) Humidity control is engaged.  
2) Blower motor is not functioning.

1) If indoor humidity is higher than desired set-
point, the blower will cycle off with the equipment.
2) Check/repair system.

Cooling or Heating cycles too 
fast or too slow (narrow or wide 
temperature swings).

1) Check the location of the thermostat for 
drafts.
2) Cycles per hour or aggressive recovery is 
improperly set.

1) Seal all air leaks behind thermostat.  Relocate 
thermostat 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.

1) Check/repair outdoor sensor or wiring.
2) Adjust the compressor lockout temperature 
setting if desired.

Cannot change system mode to 
desired setting. 

Equipment is not configured properly.

Check the standard installer set up screen to 
ensure equipment is properly configured.  

Screen does not respond prop-
erly to a button press

Screen is out of calibration

Remove thermostat from sub base and reset.   
Follow the calibration instructions when the ther-
mostat reboots. 

“No System Found” displayed on 
the thermostat

Internal error 

Reboot the thermostat via onscreen button. 

Slow or no response to any but-
ton presses 

Internal error

Remove the thermostat from the sub base and 
reset.