Lennox Commercial Touchscreen Thermostat - Setting Temperature Overrides; Hold Temperature Until

Page 11
Table 7. 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 tem-
perature limits were
reached.
Check temperature setpoints.
Check Installer Setup Numbers 0600 and 0610; modify
as needed.
not change.
The keypad is fully locked.
Check Installer Setup Number 0670 to change keypad
locked options.
Thermostat minimum off−
time is activated.
Wait up to five minutes for the system to respond.
Heating or cooling does
not come on
.
System selection not set
to Heat or Cool.
Set system Selection to correct position.
System type Selection is
incorrect.
Check Installer Setup Number 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 equip-
ment is not operating.
Check wiring.
Check Installer Setup Number 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 24Vac 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 thermo-
stat is functional. Check the heating equipment to find
the cause of the problem.
Loose or broken wire con-
nection between thermo-
stat and heating equip-
ment.
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 thermo-
stat and the heating equipment.
Both the heating and cool-
ing equipment are run-
ning at the same time.
The heating equipment is
not a heat pump but the
System Type (Installer
Setup Number 0170) is
set to Heat Pump.
Set System Type (Installer Setup Number 0170) to
match the installed heating and/or cooling equipment
ning
at
the
same
time
.
Heating and cooling wires
are shorted together.
Separate the shorted heating and cooling wires.
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 thermo-
stat is functional. Check the cooling equipment to find
the cause of the problem.
Loose or broken wire con-
nection between thermo-
stat and cooling equip-
ment.
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 ther-
mostat and the cooling equipment.
Fan does not turn on in a
call for heat (electric fur-
nace).
Fan Control in Heating is
set to Gas or Oil Furnace
(Setting 0180).
Set Fan Control in Heating to Electric Furnace (Setting
0180).
table continued on next page