20
Pub. No. 22-5183-01
69-1228—1
(Contiuned)
TROUBLESHOOTING GUIDE
Symptom Possible Cause Action
Display will not
come on.
Thermostat is not
being powered.
Check if the thermostat is mounted and
latched on the wallplate–mount and latch the
thermostat on the wallplate.
Check if the circuit breaker is tripped–reset
the circuit breaker.
Check if the fuse is blown–replace the fuse.
Check if the system switch is in the Off
position–set to Heat or Cool.
Temperature
settings will not
change (Example:
cannot set the
heating higher or the
cooling lower).
The upper or lower
temperature limits
were reached.
Check that the temperature setpoints are
within range:
Heating: 50° to 99° F (10° to 37° C)
Cooling: 50° to 99° F (10° to 37° C).