Lennox X4146 - Troubleshooting

Page 16
Troubleshooting
Symptom Possible Cause Action
Display does not come Thermostat is not being
Check to see that there
is 24V between R and C
terminals.
Display
does
not
come
on.
Thermostat
is
not
being
powered.
Check to see that
batteries are properly
installed.
Check temperature
setpoints.
Temperature settings do
not change.
Upper or lower tempera-
ture limits were reached.
Check installer set−up
numbers 0600 and
0610. Modify, if neces-
sary.
g
Keypad is fully locked.
Check installer set−up
numbers 0670 and
change keypad lock
option, if necessary.
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.
Check wiring.
Thermostat is calling for
heat (Heat ON) or cool
(Cool ON); but HVAC
ti t ti
Heating or cooling
equipment is not
operating.
Check installer set−up
number 0170 and make
sure proper system type
is selected.
()
system is not operating.
operating
.
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
numbers 0670 and
change keypad lock op-
tion, if necessary.
NOTE − Perform installer system tests (page 15) to verify thermostat control
of HVAC system.