69-0964–2
8
T7100F MICROELECTRONIC CONVENTIONAL OR HEAT PUMP THERMOSTAT
TROUBLESHOOTING GUIDE (Continued)
Symptom
Possible Cause
Action
Heating does 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 the thermostat and the
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 38. Reconfigure minimum On time (if
required).
System selection is not set to
Heat.
Set system selection to Heat.
Cooling does not
come on.
No power to the thermostat.
•
Check that the 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.
Cooling does not
come on
(continued)
Thermostat minimum Off time is
activated and wait indicator is
displayed.
•
Wait up to five minutes for the system to respond.
•
Enter Installer Setup 33. Reconfigure minimum Off time (if
required).
System selection is not set to
Cool.
Set system selection to Cool.
System On
indicator is lit, but
no heat is being
delivered.
Fan operation set to 00
(conventional heat) when it
should be set to 01 (electric
heat).
Enter Installer Setup mode number 02 and reconfigure the fan
operation.
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 equipment is not
operating.
Verify operation of heating equipment in Self-Test.
24V is present on
all terminals.
When thermostat is powered
but is not connected to
heating/cooling equipment, arc
suppression will be present
(24V ghost voltage)
Connect heating/cooling equipment to the thermostat. Voltage
will drop to zero.
69-0964–2 D.S. Rev. 12-98 Printed in Taiwan R.O.C.
www.honeywell.com/building/components
