11
Troubleshooting
SYMPTOM
CORRECTIVE ACTION
Display is blank
Install 2 fresh AA Alkaline batteries.
No heat
Set system switch to HEAT and raise set point above room temperature.
If flame icon is blinking, allow the 5 minute compressor lock-out to expire.
Check thermostat wiring and connections.
Check pilot light or HSI system on furnace.
No cool
Set system switch to COOL and lower set point below room temperature.
If snowflake icon is blinking, allow the 5 minute compressor lock-out to expire.
Check thermostat wiring & connections.
System turns on/off
Adjust the differential setting on the thermostat. A high differential decreases
too frequently or
cycle rate and a low differential increases cycle rate.
not enough
Display is not illuminated
Touch the up or down arrow key. Display will illuminate for 10 seconds.
Room temperature and
Normal (depending on differential setting).
set point disagree
Check for drafts that could quickly change the room temperature before the
system is able to correct it.
System fan runs
Set fan switch to AUTO.
continuously
Check thermostat wiring & connections.
Reduce room temperature or allow a newly installed thermostat to acclimate.
HI indicates a room temperature reading greater than 90 F (32 C).
Increase room temperature or allow a newly installed thermostat to acclimate.
LO indicates a room temperature reading less than 45 F (7 C).
HI is displayed
LO is displayed
70812-IM 12/21/06 3:06 PM Page 11