Troubleshooting - Trane TCONT402AN32DA Installer's Manual

Table 4
Symptom Possible Cause
1. Blown fuse or tripped circuit breaker.
2. Furnace power switch OFF.
Display will not come on.
3. Furnace blower compartment door or panel
Indoor temperature display is
Temperature display needs calibration.
incorrect.
Outdoor temperature display is
Temperature display needs calibration.
incorrect.
Outdoor temperature display
1. Outdoor temperature sensor open or shorted.
shows "--" and Service indicator
2. Outdoor sensor field wiring open or shorted.
on solid.
Cannot set Heating setpoint
Deadband between Heating and Cooling set to high.
above 80 degrees
Service indicator flashing on and
off at ISU steps 5 and 8 or Service JP1 Dual Fuel jumper setting does not agree with
and Heat indicators flashing on ISU selections.
and off.
Service indicator flashing on and
Control EEPROM write error.
off.
Service indicator solid on and "--"
Indoor temperature sensor open or shorted.
in temperature display.
1. Upper and/or lower temperature limits were
Temperature setting will not
change. (Example: Cannot set
2. "Keypad locked" is displayed on LCD.
heating higher or cooling lower).
Room temperature overshoots
Oversized heating or cooling equipment. Control
when Energy Savings Key ($) is
cannot respond fast enough to prevent
used or the Heat/Cool settings is
overshooting.
changed more than 2 degrees.
1. System Mode not set to Heat.
2. Minimum off time delay being enforced.
Heating will not come on. 3. Loose connection to control or system.
4. Heating system requires service or
1. System Mode not set to Cool.
2. Minimum off time delay being enforced
Cooling will not come on. 3. Loose connection to control or system.
4. Cooling system requires service or
1. The heating equipment turns on the
Cool ON or Heat ON is displayed,
but no warm or cool air is coming
from the registers. 2. Heating or cooling equipment is not
Control does not respond to 1. "Keypad locked" is displayed on LCD.
keypad presses. 2. Keypad failure.
Fan does not operate properly in 1. Incorrect wiring.
heat or cool mode. 2. Heating or cooling equipment inoperative.
1. Fan mode set to ON.
Fan runs all the time.
2. Shorted control wiring.
Cooling cycle too fast or too slow.
The location of the control and/or the size of the
(Narrow or wide temperature
cooling system may be influencing the cycle rate.
swing).
Heating cycle too fast or too slow.
The location of the control and/or the size of the
(Narrow or wide temperature
heating system may be influencing the cycle rate.
swing).
The installer has selected remote indoor sensor in
ISU 36 but has none connected, a wire is broken/not
ROOM and SERVICE icon flashing
connected or the sensor has failed open. This
while continuing to display indoor
control will default to the on-board sensor if a
room temperature
remote indoor sensor were hooked up and failed to
report properly.
14

Troubleshooting

loose or not properly installed.
reached.
control requires replacement.
control requires replacement.
fan when the furnace has warmed up to a
setpoint.
operating.
Installer's Guide
Action
1. Replace fuse or reset breaker.
2. Turn switch to ON.
3. Replace door panel in proper position to engage safety interlock or
door switch.
Calibrate Sensor - User Setup Step 59.
1. Calibrate Sensor - User Setup Step 60.
2. Disconnect outdoor sensor from controls terminal block and check the
sensor and field wiring resistance value - Table 2.
1. Replace outdoor sensor.
2. Check / repair outdoor sensor field wiring.
Decrease Deadband setting - User Setup Step 52.
Cut JP1 for Dual Fuel applications.
Press any key and Check / Re-enter Setup Choices.
Replace Control
1. Check the temperature setpoints:
Heating limits are 40 - 85F.
Cooling limits are 65 - 90F.
2. Unlock keypad - press Up+Down arrow together until icon disappears.
Set Control Response rate to "Fast" - ISU Step 34.
1. Set Mode to heat and raise the setpoint above room temperature.
2. If heating does not come on within 5 minutes, Check Heating.
3. Check / Repair connections.
4. Repair system / Replace control.
1. Set Mode to cool and lower the setpoint below room temperature.
2. If cooling does not come on within 15 minutes, contact servicer.
3. Repair connections.
4. Repair system / Replace control.
1. Wait one minute after Heat ON is displayed
and then check the registers.
2. Check Heating and Cooling system.
1. Unlock keypad - press Up+Down arrow together until "Keypad locked"
disappears.
2. Replace Control.
1. Correct wiring.
2. Repair system.
1. Set fan mode to AUTO.
2. Check / Repair wiring.
Verify cycle rate adjustment ISU Steps 20 & 22.
Verify cycle rate adjustment ISU Steps 24.26.28.30 & 32.
Select proper option for ISU 36, repair wire, connection, or sensor.
Pub. No. 18-HD29D3-4