Honeywell SERIES 2000 T7300D - Manual (Page 9)

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T7300D SERIES 2000 COMMERCIAL MICROELECTRONIC 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
thermostats. Example: cool
setpoint=72, deadband=3, heat
setpoint=68, changing heat
setpoint to 70 will automatically
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 or RH 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 or RC and Y 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
Fan operation set for 0
(conventional heat) when it
should be set for 1
(electric heat). Enter Installer Setup number 2 and reconfigure the fan
operation.
warm or cool air is
coming from the
registers.
Conventional 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.
Heating or cooling equipment is
not operating. Verify operation of heating or cooling equipment in self-test.