Page 20
Troubleshooting
Symptom
Possible Cause
Action
Display does not come
on.
Thermostat is not being
powered.
1− Check to see that there
is 24V between R and C
terminals.
2− Check to see that bat-
teries are properly
installed.
Temperature settings do
not change.
Upper or lower tempera-
ture limits were reached.
1− Check temperature set-
points.
2− Check installer set−up
numbers 0600 and 0610.
Modify, if necessary.
not change.
Keypad is fully locked.
Check installer set−up
number 0670 and change
keypad lock option, if nec-
essary.
Thermostat minimum−off
time is activated.
Wait up to 5 minutes for
the system to respond.
Heating or cooling does
not come on
System selection has not
been set to heat or cool.
Select proper system
mode.
not come on.
System type selection is
incorrect.
Check installer set−up
number 0170 and make
sure proper system type
is selected.
Thermostat is calling for
heat (Heat ON) or cool
(Cool ON); but HVAC sys-
tem is not operating.
Heating or cooling equip-
ment is not operating.
1− Check wiring.
2− Check installer set−up
number 0170 and make
sure proper system type
is selected.
3− Verify operation of
equipment in system test
mode.
Thermostat does not
respond when touch
screen is pressed.
Keypad is fully locked.
Check installer set−up
number 0670 and change
keypad lock option, if nec-
essary.
NOTE − Perform installer system tests (page 19) to verify thermostat
control of HVAC system.
