Product Overview

TB7100A1000 MULTIPRO™ MULTISPEED AND MULTIPURPOSE THERMOSTAT
23 63-2675—04
TROUBLESHOOTING (TABLE 12)
Table 12. Troubleshooting.
Symptom Possible Cause Action
Display does not come on. Thermostat is not being powered. Check for 24 Vac between C and Rc.
Check that AAA batteries are installed correctly
and are good.
Temperature settings do not
change.
The upper or lower temperature limits
were reached.
Check temperature setpoints.
Check ISU 0600 and 0610; modify as needed.
The keypad is fully locked. Check ISU 0670 to change keypad locked
options.
Heating or cooling does 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 or
Cool.
Set system Selection to correct position.
System type Selection is incorrect. Check ISU 0170 and make sure correct System
type is chosen.
Thermostat is calling for Heat
(Heat on) or Cool (Cool on) but
no heating or cooling is
running.
Heating or cooling equipment is not
operating.
Check wiring.
Check ISU 0170 and make sure correct system
type is chosen.
Verify operation of equipment in System Test
mode.
Heat does not turn on (Heat On
is solid in the display).
Heating equipment failure. Check for 24 Vac at the equipment on the
secondary side of the transformer between
power and common. If voltage is not present,
check the heating equipment to find the cause
of the problem.
Check for 24 Vac between the heat terminal
(W) and transformer common. If 24 Vac is
present, the thermostat is functional. Check
the heating equipment to find the cause of the
problem.
Loose or broken wire connection
between thermostat and heating
equipment.
Check for 24 Vac between the heat terminal
(W) and transformer common. If voltage is not
present, check wire connection (loose or
broken) between the thermostat and the
heating equipment.
Cooling does not turn on (Cool
On is solid in the display).
Cooling equipment failure. Check for 24 Vac at the equipment on the
secondary side of the transformer between
power and common. If voltage is not present,
check the cooling equipment to find the cause
of the problem.
Check for 24 Vac between the cool terminal (Y)
and transformer common. If 24 Vac is present,
the thermostat is functional. Check the cooling
equipment to find the cause of the problem.
Loose or broken wire connection
between thermostat and cooling
equipment.
Check for 24 Vac between the cool terminal (Y)
and transformer common. If voltage is not
present, check the wire connection (loose or
broken) between the thermostat and the
cooling equipment.
Fan does not turn on in a call
for heat (electric furnace).
Fan Control in Heating is set to System
Controls Fan (Setting 0180).
Set Fan Control in Heating to Thermostat
Controls Fan (Setting 0180).
Heat pump puts out cool air in
the heat mode and warm air in
the cool mode.
Changeover Valve (ISU 0190) is not
configured to match the changeover
required by the installed heat pump.
Set Changeover Valve (ISU 0190) to match the
changeover required by the installed heat
pump.