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18-HD66D1-4
Section 9. Troubleshooting
Troubleshooting
Symptom
Possible Cause
Action
COMM LED is not
flashing the ap-
propriate number
of devices
Loss of 24VAC between power (R) and common (B)
Check for proper incoming 24VAC power at
Zone Panel 24v Trans terminals
One or more communicating devices is not com-
municating
•
~12VDC between D & B = Proper communication
•
~16VDC between D & B = Loss of communication
•
Less than ~12VDC between D & B = grounded or no power
Note: Voltage may fluctuate while devices are transmitting on the
communication bus
Access the Summary Table on the 950/1050
Control to view the communication status of all
discovered communicating devices.
Troubleshoot the offline device utilizing the units
service facts
COMM LED is
flashing rapidly
One or more communicating devices has corrupted
the communication traffic
•
~12VDC between D & B = Proper communication
•
~16VDC between D & B = Loss of communication
Fix/replace the communicating device which is
causing the excessive communication traffic
COMM LED is
steady “ON”
Zone Panel is not communicating
•
~16VDC between D & B = Loss of communication
Check for open or grounded field wiring
An Err 126 may be displayed on comfort control
Zoning Disabled
is displayed on the
Zone Panel user
interface
Zoning has not been enabled on the Comfort
Control
On the control, enable zoning in the Installer
Setup > Standard settings
Zoning has been disabled due to a system fault
On the control, check for critical/major alerts in
Diagnostic > Current Alerts
Primary Zone Panel dip switch is set to Zones 5-8
Set dip switch of primary Zone Panel to Zones
1-4
Damper is open
when damper
should be closed
Damper not wired correctly
Verify damper wiring is connected and has not
been reversed
Damper actuator has failed
Replace damper actuator
Damper blade is stuck/broke
Replace the damper assembly
Damper is closed
when damper
should be open
Damper not wired correctly
Verify damper wiring is connected and has not
been reversed
Damper actuator has failed
Replace damper actuator
Damper blade is stuck/broke
Replace the damper assembly
The manufacturer has a policy of continuous product and product data improvement
and reserves the right to change design and specifications without notice.
Representative-only illustrations included in this document.
6200 Troup Highway
Tyler, TX 75707
© Trane U.S. Inc. 2017
