18
Common Troubleshooting Issues
Compressor Does Not Start Immediately
• For normal operation without changing modes of operation,
the compressor will not restart until 5 minutes (the minimum
off time) have expired since it shut off last.
• A minimum demand of 0.5°F is required before the heat
pump (heating or cooling) will start up.
• The system will wait 5 minutes following detection of a fault
condition before attempting a restart.
Compressor Does Not Shut Off Immediately
• For normal operation without changing modes of operation,
the compressor will not shut off until 5 minutes (the minimum
run time) have expired since it started last.
The Outdoor Fan Does Not Shut Off When the
Compressor Does
• For normal operation the outdoor fan is designed to run for
30 seconds after the compressor shuts off.
In Cooling, the Blower Slows Down and the Unit
Is Not Responding to Room Temperature
• Slowing of blower speed and suspension of normal capacity
control will occur when the unit goes into Dehumidifi cation.
If conditions for dehumidifi cation persist, the unit will run
cycles of 10 minutes in dehumidifi cation, 5 minutes in normal
cooling (responding to room temperature).
In Heating, the Unit Appears to be Cooling
• During heat pump heating when the outdoor temperature
is in the mid-30’s (°F) or lower, the unit will periodically
go into a Demand Defrost operation. After power to the
controller is turned on, the fi rst defrost may occur as soon
as 34 minutes after startup. Subsequently, defrost will be
determined by outdoor coil temperature or by the maximum
time between defrosts of 6 hours (if the coil temperature is
low enough).
In Heat Pump Heating, the Furnace Runs At the
Same Time
• The indoor (backup) heating system will operate during
defrost cycles. (See above item.)
In Heating, the Furnace or Electric Heat Runs
Instead of the Heat Pump
• The indoor backup heat equipment will run instead of the
heat pump if (a) the outdoor air temperature is below the
Minimum Heat Pump Usage Limit, (b) the heat pump is in
a fault condition, or (c) the heat pump is not able to satisfy
the demand (after a time delay).
The System Is In AUTO Mode, but It Won’t Switch
Quickly From Heating to Cooling (or the Reverse)
• There is a confi gurable delay (Auto Changeover Time)
between operating in heating and restarting in cooling (or
the reverse) when in AUTO mode. The default delay for
this changeover is 60 minutes.
Abnormal – If the red LED near the dc power plug is not on,
then the AC/DC power supply is not connected or not working.
If the red LED 1 ½” from the lower right edge does not fl ash,
the module is not communicating properly on the iQ bus.
iQ Zone System Confi guration
Normal – Check the ZONING DATA screen from the SERVICE
INFORMATION menu (shown on page 11). In the lower
portion of the screen the zone weights shown should match
the intended values, and they should add up to 100(%).
Z O N E M O D U L E S TAT U S
PREVIOUS
M O D
1 Z 1 0
2 Z 2 0
3 Z 3 X
4 Z 4 0
5 Z 5 0
6 Z
7 Z
8 Z
9 Z 1 0
1 0 Z 1 2
M O D
1 1 Z 1 0
1 2 Z 1 0
1 3 Z 2 0
1 4 Z 2 3
1 5 Z 2 0
1 6 Z 2 0
1 7 Z 3 X
1 8 Z 3 X
1 9 Z 4 2
2 0 Z 4 0
M O D
2 1 Z 5 0
2 2 Z
2 3 Z
2 4 Z
2 5 Z
2 6 Z
2 7 Z
2 8 Z
2 9 Z
3 0 Z
3 1 Z 2 0
3 2 Z
Press the key to view the ZONE MODULE STATUS screen
(shown here). Every module installed in the system should show
up on this list with the proper zone identifi cation number after
the “Z”, followed by a “0”. For example, “23Z40” is module 23
in zone 4. The “0” indicates normal functioning. Zone numbers
should only appear with module numbers that were intended to
be assigned. For master zone modules 1-8, the zone number
must match the module number.
Abnormal – If any zone weight shown in the ZONING DATA
screen is incorrect, or if the total for the eight zones is not
100(%), make the appropriate corrections from the zone
thermostat for the zone(s) which require(s) correction.
If an installed zone module does not show up in the ZONE
MODULE STATUS screen with an assigned zone number,
such as with module 25 in the fi gure, check the wiring to that
zone module. If the zone number is wrong or if the wrong
module number shows up as used, the module needs to be
reconfi gured. If the last character after the zone number is
not “0”, look for the following problems:
• “1” may indicate a disconnected damper motor connector.
• “2” may indicate a damper that is jammed due to blockage
from a foreign object or damage or dirt on the internal
transmission.
• “3” may indicate that a zone thermostat is not connected
properly to its associated master zone module (1-8).
• “X” may indicate that a module is assigned but not
communicating.