8
PROBLEM
POSSIBLE CAUSE
SOLUTION
The digital display does not
light up.
1. No power to the stat or sys-
tem equipment.
2. Lightstat switch in OFF
position.
1. Check the system low
voltage power.
2. Check the system ON/OFF
switch.
3. Check the circuit breaker.
The display works but the
heat does not come on.
The room temperature
is above the factory pro-
grammed limit of the thermo-
stat.
Check again when the room
temperature falls below the
factory programmed limit.
The display works but the
cooling does not come on.
(some stats are heating only
and this would not apply).
The room temperature is
below the factory programmed
limit of the thermostat.
Check again when the room
temperture goes above the
factory programmed limit.
Setback indicator stays ON or
OFF.
1. Improper light sensor
adjustment.
2. Thermostat location is not
optimal.
1. Adjust light sensor
(optional)
2. Move thermostat if
necessary.
Review locations to avoid
(page 2).
Fan runs continuously with
thermostat system switch set
to OFF.
Fan switch set to the ON
position.
Move fan switch to the AUTO/
OFF position.
Control relay on heating unit
chatters.
Low voltage
Troubleshooting your Lightstat thermostat:
