Trane TCONT900AC43UA Installer's Manual page 21

Symptom
Outdoor temperature display
shows "--" or the outdoor
temperature is not displayed.
Indoor temperature display shows
"--".
Temperature setting will not
change (e.g. Cannot increase
heating setpoint or reduce cooling
setpoint).
Room temperature overshoots
when the Heat/ Cool setting is
changed more than 2 degrees.
Heating will not come on.
Cooing will not come on.
Heat ON or Cool ON is displayed,
but no warm air or cool air is
coming from the registers.
Control does not respond to
keypad screen presses.
Fan does not operate properly in
heat or cool mode.
Fan runs all of the time.
Fan is set to "On" but not running. 1. Trane Proprietary Humidity
Cooling cycles too fast or too slow
(narrow or wide temperature
swing).
Table 7. Troubleshooting Information
Possible Cause
1. Outdoor temperature sensor
open, shorted, not reporting, or
not installed.
2. Outdoor sensor field wiring
open or shorted.
Indoor temperature sensor open
or shorted.
1. Upper and/or lower
temperature limits were reached.
2. Keys are fully locked. "Screen
Locked" is displayed on LCD.
1. Oversized heating/cooling
equipment under current
conditions. Control cannot
respond fast enough to prevent
overshooting.
2. Improper location of comfort
control.
1. System Mode not set to Heat.
2. Minimum off time delay being
enforced.
3. Loose connection to control or
system.
4. Heating system may need
service.
1. System Mode not set to Cool.
2. Minimum off time delay being
enforced.
3. Loose connection to control or
system.
4. Cooling system may need
service.
1. The heating equipment turns
on the fan when the furnace has
warmed up.
2. Heating or cooling equipment
is not operating.
1. Keys are fully locked. "Screen
Locked" is displayed on LCD.
2. Keypad failure.
1. Heating or cooling equipment
inoperative.
1. Fan mode is set to ON -
continuous.
2. Fan scheduled to run
continuously.
3. Indoor equipment may need
service.
Control.
The location of the control and/or
the size of the cooling system
may be influencing the cycle rate.
1. Replace/Install outdoor sensor.
2. Check/repair outdoor sensor field
wiring.
Replace control.
1. Check the temperature setpoints:
Heating limits (ISU 0600) are 40°F - 90°F
(4.4°C - 32.2°C).
Cooling limits (ISU 0610) are 60°F - 99°F
(15.5°C - 32.2°C).
2. Unlock keypad - ISU 0670.
1. Set Control Response rate to
"Aggressive" - ISU 0680, 0690
2. Select a location that prevents the
Comfort Control from being directly
exposed to air currents from supply
registers.
1. Set Mode to heat and raise the
setpoint above room temperature.
2. If heating does not come on within 5
minutes, checking heating equipment.
3. Check/repair connections.
4. Repair system.
1. Set Mode to cool and lower the
setpoint above room temperature.
2. If cooling does not come on within 15
minutes, checking cooling equipment.
3. Check/repair connections.
4. Repair system.
1. Wait one minute after Heat ON is
displayed and then check the registers.
2. Check Heating and/or Cooling
equipment.
1. Unlock keypad - ISU 0670.
2. Replace control.
1. Repair system.
1. Set fan mode to AUTO or CIRC.
2. Reprogram fan schedule, if desired.
3. Check Indoor equipment.
Verify that the Dehumidification setpoint
is below the actual indoor humidity. See
"Trane Proprietary Humidity Control" on
page 19 for additional information.
Verify/adjust cycle rates - ISU 0220,
0230.
21
TCONT900AC43UA
Action
Pub. No. 18-HD32D1-2
69-2079—05