XT302C DELUXE PROGRAMMABLE HEAT-COOL THERMOSTAT
11
69-1213—1 (T8624)
Pub. No. 18-HD25D7-5
TROUBLESHOOTING (Continued).
Symptom
Possible Cause
Action
Heating will not come
on.
No power to the
thermostat.
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.
Heating will not come
on.
Thermostat minimum off
time is activated.
Wait up to five minutes for the system to respond.
System selection is not
set to Heat.
Set system selection to Heat.
Heating setpoint is below
room temperature.
Check heating setpoint. Set heating setpoint to desired temperature.
Cooling will not come
on.
No power to the
thermostat.
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.
Thermostat minimum off
time is activated.
Wait up to five minutes for the system to respond. Enter Installer Setup
number 39. Reconfigure minimum off time (if required).
System selection is not
set to Cool.
Set system selection to Cool.
Cool setpoint is above
room temperature.
Check cooling setpoint. Set cooling setpoint to desired temperature.
Heating or cooling
come on momentarily
and shut off
Heat or cool circuit is
opening up or becoming
high impedance.
Add resistor in parallel with load or install interface relay.
System on indicator
(flame=heat,
snowflake=cool)
displays, but no
Heating equipment turns
on the fan when the
furnace has warmed up
to a setpoint.
Wait a minute after seeing the on indicator and then check the registers.
warm or cool air is
coming from the
registers.
Heating or cooling
equipment is not
operating.
Verify operation of heating or cooling equipment in self-test.
Outdoor temperature
not displayed
Option not activated.
Enter Installer Setup number 24 and set to 1. Thermostat must have OT
terminals and a TAYSENS100A installed.
or is incorrect.
Outdoor sensor is
connected incorrectly.
Refer to TAYSENS100A installation instructions and check wiring
between the thermostat and sensor.
Wrong sensor.
Replace sensor with TAYSENS100A sensor.
Filter expired.
Refer to the
Filter Indication section in the Owner’s Guide, Pub.
No. 22-5127-04
System on indicator
reads Filter and
backlight is flashing.
Filter expired.
Refer to the
Filter Indication section.
Time displaying digits
as three E’s (EEE).
Internal memory failure.
Contact distributor or retailer.
