Honeywell TH8320U Installation Instructions Manual page 20

TH8320U AND TH8321U TOUCH SCREEN PROGRAMMABLE THERMOSTATS
TROUBLESHOOTING (SEE TABLE 8)
Symptom
Display does not come on.
Temperature settings do not
change.
Heating or cooling does not come
on.
Thermostat is calling for Heat
(Heat on) or Cool (Cool on) but no
heating or cooling is running.
Thermostat does not respond
when touch areas are pressed.
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
69-1706 G.H. 01-04
Table 8. Troubleshooting.
Possible Cause
Thermostat is not being
powered.
The upper or lower temperature
limits were reached.
The keypad is fully locked.
Thermostat minimum off-time is
activated.
System selection is not set to
Heat or Cool.
O/B terminal is not set correctly
(Heat Pumps only).
System type Selection is
incorrect.
Heating or cooling equipment is
not operating.
The keypad is locked.
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9
Action
Check for 24 Vac between C and Rc.
Check that AAA batteries are installed
correctly and are good.
Check temperature setpoints.
Check Installer Setup Numbers 0600 and
0610; modify as needed.
Check Installer Setup Number 0670 to
change keypad locked options.
Wait up to five minutes for the system to
respond.
Set system Selection to correct position.
Check Installer Setup Number 0190 and
set correctly.
Check Installer Setup Number 0170 and
make sure correct System type is
chosen.
Check wiring.
Check Installer Setup Number 0170 and
make sure correct system type is chosen.
Verify operation of equipment in System
Test mode.
Check Installer Setup Number 0670 to
change keypad locked options.
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