GVZC20 Service Manual

TROUBLESHOOTING
103
NETWORK TROUBLESHOOTING
If a network communication error code has occurred, use
the following steps to help troubleshoot the system. (For
network communication error codes, refer to the table below
and the tables of error codes for outdoor unit and indoor
unit.)
After any wiring changes have been made or DS1 dip
switches on the outdoor unit control board have been
changed, apply power to the system and see if the error
codes have cleared.
1. Conrm low voltage wiring is correct per installation
instructions. Check for miswiring. (i.e. Terminal 1 and 2
is reversed.)
NOTE: A removable plug connector is provided with the
control to make thermostat wire connections. This plug
may be removed, wire connections made to the plug, and
replaced. It is strongly recommended that you do not
connect more than two wires into a single terminal in the
eld because there is a risk of the wires becoming loose,
which may result in intermittent operation.
2. Check wires for damage. (i.e. Broken wire at terminal,
broken inside wire nuts or damaged cable between
units.)
3. Perform continuity check on wires to make sure cable is
OK. Replace the cable if necessary.
4. Change both dip switches of DS1 on the outdoor unit
control board to the opposite position. See image above.
The integrated control module has some onboard tools that
can be used to troubleshoot the network. These tools are:
red communications LED, green receive (Rx) LED, and the
learn button.
• Red communications LED – Indicates the status of the
network. The table below indicates the LED status and
the corresponding potential problem.
• Green receive LED – Indicates network tra󰀩c. The table
below indicates the LED status and the corresponding
potential problem.
• LEARN button – Used to reset the network. Press the
button for approximately 5 seconds to reset the network.
LED COLOR LED Status Indication Probable Causes Corrective Actions
Off Normal condition • None • None
1 Flash Communications failure
• Unknown packet is received
• Communications failure
• Depress learn button
• Verify wiring connection
2 Flash Out-of-box reset
• Control power up
• Learn button depressed
• None
Off
No power
Communications error
• No power to unit
• Open fuse
• Communication error
• Check circuit breakers and fuses;
Reset/Replace if needed
• Reset network by depressing learn button
• Check communication wires (terminal
1/terminal 2 wires); Replace if needed
• Check for shorts in low voltage wiring.
1 Steady Flash No network found
• Broken/disconnected
communication wire(s)
• Unit is installed as a
legacy/traditional system
• Check communication wires (terminal
1/terminal 2 wires); Replace if needed
• Check installation type (legacy/traditional or
communicating)
Rapid Flashing Normal network traffic • Control is “talking” on network as
expected
• None
On Solid
Terminal 1/Terminal 2
miss-wire
• Terminal 1 and Terminal 2 wires
reversed at indoor unit, thermostat,
or outdoor unit
• Short between terminal 1 and
terminal 2 wires
• Short between terminal 1 or
terminal 2 two wires and terminal C
(24VAC) or terminal R (24VAC,
COM)
• Check communication wires (terminal
1/terminal 2 wires); Replace if needed
Red Communications
LED Outdoor unit
control board: (H1P)
Indoor unit control
board :(H2P)
Green Receive LED
Outdoor unit control
board:(H2P)
Indoor unit control
board:(H3P)