TROUBLESHOOTING
74
NETWORK TROUBLESHOOTING
Communications is achieved by taking the difference
between a positive dc signal and a negative dc signal.
The positive dc signal is termed “data 1” or “1’. Data 1 is
positive with respect to ground (or common). The nega-
tive dc signal is termed “data 2” or “2”. Data 2 is negative
with respect to ground (or common).
Verify that the bus DS1 dip switches are in the ON position.
Data 1 should be approximately 2.8 volt dc. Data 2 should
be approximately 2.2 volt dc. The voltage difference
between data 1 and data 2 should be approximately 0.6
volt dc.
If the voltage difference is not .6 VDC, turn OFF DS1
switches Data 1 and Data 2. Reset Power and check for
.6 DCV.
OFF
ON
1
2
The ComfortNet™ system is a fully communicating system,
constituting a network. Occasionally the need to trou-
bleshoot the network may arise. The integrated control
module has some on-board tools that can be used to trou-
bleshoot 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 traffic. 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 Status
Indication
Probable Causes
Corrective Actions
Off
Nominal condition
● None
● none
1 Flash
Communications Failure
● Unknown packet is received
● Depress learn button
2 Flash
Out-of-box reset
● Control power up
● Learn button depressed
● None
Off
No power
Communications error
● No power to Outdoor unit
● Open fuse
● Communication error
● Check circuit breakers and fuses; Replace if needed
●Reset network by depressing learn button
● Check communication wires (data 1/ data 2 wires);
Replace if needed
1 Steady Flash
No network found
● Broken/ disconnected communication
wire(s)
● AC is installed as a legacy/ traditional
system
● Check communication wires (data 1/ data 2 wires);
Replace if needed
● Check installation type (legacy/ traditional or
communicating)
● Check data 1/ data 2 voltages
Rapid Flashing
Nominal network traffic
● Control is "talking" on network as expected ● none
On Solid
Data 1/Data 2 miss-wire
● Data 1 and data 2 wires reversed at indoor
unit, thermostat, or outdoor unit
● Short between data 1 and data 2 wires
● Short between data 1 or data 2 wires
● Check communication wires (data 1/ data 2 wires);
Replace if needed
● Check data 1/ data 2 voltages
LED COLOR
Red Communications LED
(H1P)
Green Receive LED
(H2P)
OUTDOOR UNIT
