Thermostat Menu; Diagnostics; Network Troubleshooting - Goodman *CVC96 Installation Instructions Manual

T M
HERMOSTAT ENU
If this furnace is installed with a communicating compatible heat pump, the system is recognized as a dual fuel system. The
balance point temperature should be set via the thermostat.
D
IAGNOSTICS
Accessing the furnace's diagnostics menu provides ready access to the last six faults detected by the furnace. Faults are stored
most recent to least recent. Any consecutively repeated fault is stored a maximum of three times. Example: A clogged return air
filter causes the furnace limit to trip repeatedly. The control will only store this fault the first three consecutive times the fault
occurs. Navigate to the diagnostics menu as described above in the thermostat installation manual.
NOTE: It is highly recommended that the fault history be cleared when performing maintenance or servicing the furnace.
N
ETWORK TROUBLESHOOTING
Communications is achieved by taking the difference between two dc signals. The signals and transmission lines are referred to
as "data 1" and "data 2". Each transmission line is biased to approximately 2.5Vdc. During data reception/transmission, the
data lines vary between +5V and ground. (When data 1 is increasing towards +5V, data 2 is decreasing towards ground and when
data 1 is decreasing towards ground, data 2 is increasing towards +5V. Typically, the data 1 line is approximately 2.6Vdc and the
data 2 transmission line is approximately 2.3Vdc. The voltage difference between data 1 and data 2 is typically 0.2 to 0.6 Vdc.
The ComfortNet™ system is a fully communicating system, and thus, constitutes a network. Occasionally the need to troubleshoot
the network may arise. The integrated furnace control has some on-board tools that may be used to troubleshoot the network.
These tools are: red communications LED, green receive (Rx) LED, and 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 traffic. The table below indicates the LED status and the corresponding potential
problem.
• Learn button – Used to reset the network. Depress the button for approximately 2 seconds to reset the network.
Red
Communications
LED
Green Receive
LED
LED Description Possible Cause
Off Normal condition None
1 Flash Communications Communications
Failure Failure
2 Flashes Out-of-box reset •Control power up
•Learn button depressed
Off •Nopower •No power to furnace
•Communications •Open fuse
error
•Communications error
1 Steady No network •Broken/ disconnected
Flash data wire(s)
found
•Furnace is installed
as a legacy/ traditional
system
Rapid Normal network Control is "talking" on
network as expected
Flashing traffc
On Solid Data 1/ Data 2 •Data 1 and data 2 wires
miss-wire reversed at furnace,
thermostat, or CT™
compatible outdoor AC/
HP
•Short between data 1
and data 2 wires
•Short between data 1
or data 2 wires and R
(24VAC) or C (24VAC
common)
Corrective Action
None
•Depress Learn Button
•Verify that bus BIAS and
TERM dipswitches are in
the ON position.
None
•Check fuses and circuit
breakers; replace/reset
•Replace blown fuse
•Check for shorts in low
voltage wiring in furnace/
system
•Reset network by
depressing learn button
•Check data 1/ data 2
voltages
•Check communications
wiring (data 1/ data 2
wires)
•Check wire connections
at terminal block
•Verify furnace installation
type (legacy/ traditional
or communicating) Check
data 1/ data 2 voltages
None
•Check communications
wiring (data 1/ data 2
wires)
•Check wire connections
at terminal block
•Check data 1/ data 2
voltages
46
Comments
None
•Depress once quickly for
a power-up reset
•Depress and hold for 2
seconds for an out-of-box
reset
None
•T urn power OFF prior to
repair
•T urn power OFF prior to
repair
•Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
•Verify data1 and data
voltages as described
above
None
•T urn power OFF prior to
repair
•Verify wires at terminal
blocks are securely
twisted together prior to
inserting into terminal
block
•Verify data1 and data
voltages as described
above