62-0124—3
9
T7300E SERIES 2000 COMMERCIAL MICROELECTRONIC HEAT PUMP THERMOSTAT
TROUBLESHOOTING GUIDE (Continued).
Symptom
Possible Cause
Action
Temperature settings
change from original
setting.
Trying to set heating and
cooling setpoints too close
together. There is a deadband
in automatic changeover
thermostat models. Example:
cool setpoint=72,
deadband=3, heat
setpoint=68, changing heat
setpoint to 70 will auto-
matically change the cool
setpoint to 73.
•
Check that the heating setpoint is lower than the
cooling setpoint.
Room temperature is
out of control.
Remote temperature sensing
is not working.
Checkout all remote sensors.
Heating will not
come on.
No power to the thermostat.
•
Check that X terminal is connected to the system
transformer.
•
Check for 24 Vac between X and R 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 system switch at the equipment is in
the Off position—set to 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 and wait indicator
is displayed.
•
Wait up to five minutes for the system to respond.
•
Enter Installer Setup number 38. Reconfigure minimum off
time (if required).
System selection is not set
to Heat.
Set system selection to Heat.
Cooling will not
come on.
No power to the thermostat.
•
Check that X terminal is connected to the system
transformer
•
Check for 24 Vac between X and R 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 system switch at the 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 and wait indicator
is displayed.
•
Wait up to five minutes for the system to respond.
•
Enter Installer Setup number 33. Reconfigure minimum off
time (if required).
System selection is not set to
Cool.
Set system selection to Cool.
System on indicator
(flame=heat,
snowflake=cool) is
displayed, but no
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.
