37
T
ROUBLESHOOTING
N
ETWORK
T
ROUBLESHOOTING
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 negative dc signal is termed “data 2” or “2”.
Data 2 is negative with respect to ground (or common).
Data 1 should be approximately 2.8 volts dc. Data 2 should be
approximately 2.2 volts dc. The voltage difference between data
1 and data 2 should be approximately 0.6 volts dc.
Verify that the bus DS1 dip switches are in the ON position.
TERM
OFF ON
1
2
The ComfortNet™ system is a fully communicating system, con-
stituting a network. Occasionally the need to troubleshoot the
network may arise. The integrated control module has some on-
board 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 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 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 bu on
2 Flash
Out-of-box reset
●
Control power up
●
Learn bu on depressed
●
None
Off
No power
Communications error
●
No power to Outdoor unit
●
Open fuse
●
Communica on error
●
Check circuit breakers and fuses; Replace if
needed
●
Reset network by depressing learn bu on
●
Check communica on wires (data 1/ data 2
wires); Replace if needed
1 Steady Flash
No network found
●
Broken/ disconnected communica on wire(s)
●
AC is installed as a legacy/ tradi onal system
●
Check communica on wires (data 1/ data 2
wires); Replace if needed
●
Check installa on type (legacy/ tradi onal 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 and R (24VAC) or
C (24VAC common)
●
Check communica on 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)
