Trane XT500C Installer's Manual page 12

XT500C DELUXE PROGRAMMABLE HEAT-PUMP THERMOSTAT
TROUBLESHOOTING GUIDE (Continued).
Symptom Possible Cause
Heating will not come Thermostat minimum off
on (continued). time is activated.
System selection is not
set to Heat.
Heating setpoint is below
room temperature.
Cooling will not come No power to the
on. thermostat.
Thermostat minimum off
time is activated.
System selection is not
set to Cool.
Cool setpoint is above
room temperature.
Heating or cooling Heat or cool circuit is
comes on momentarily opening up or becoming
and shuts off high impedance.
Heating equipment turns
System on indicator
on the fan when the
(flame=heat,
furnace has warmed up
snowflake=cool)
to a setpoint.
displays, but no
warm or cool air is
Heating or cooling
coming from the
equipment is not
registers.
operating.
Option not activated.
Outdoor temperature
not displayed
or is incorrect.
Outdoor sensor is
connected incorrectly.
Wrong sensor.
Filter expired.
System on indicator Filter expired.
reads Filter and
backlight is flashing.
Time displaying digits Internal memory failure.
as three E's (EEE).
LED is lit System switch set to Em.
Ht.
Compressor failure.
Pub. No. 18-HD25D2-2
69-1404 G. H. 8-00
69-1404
Action
Wait up to five minutes for the system to respond.
Set system selection to Heat.
Check heating setpoint. Set heating setpoint to desired temperature.
Check for 24 Vac between R and W terminals.
If missing 24 Vac:
Check if the circuit breaker is tripped—reset the circuit breaker.
Check if the system fuse is blown—replace the fuse.
Check if the power switch on the HVAC equipment is in the Off
position—set to the On position.
Check wiring between thermostat and HVAC equipment—replace any
broken wires and tighten any loose connections.
If 24 Vac is present, proceed with troubleshooting.
Wait up to five minutes for the system to respond. Enter Installer Setup
number 39. Reconfigure minimum off time (if required).
Set system selection to Cool.
Check cooling setpoint. Set cooling setpoint to desired temperature.
Add resistor in parallel with load or install interface relay.
Wait a minute after seeing the on indicator and then check the registers.
Verify operation of heating or cooling equipment in self-test.
Enter Installer Setup number 24 and set to 1. Thermostat must have OT
terminals and a TAYSENS100A installed.
Refer to TAYSENS100A installation instructions and check wiring
between the thermostat and sensor.
Replace sensor with TAYSENS100A sensor.
Refer to the Filter Indication section in the Owner's Guide, Pub.
No. 22-5128-02.
Refer to the Filter Indication section.
Contact distributor or retailer.
Move system switch to Heat or Auto.
Contact service technician.
Printed in Taiwan R.O.C.
12
American Standard Inc.
Troup Highway
Tyler, TX 75711-9010