DCN: 141-00940-09 11/02/07
10
Control Unit Status LEDs
The Control Unit has LEDs on the circuit board to show
system status
and
relay output states
. When
the relay output LED’s are on, the relay is on.
Relay Output LEDs
LED
Function
Control Unit Output
H1
Heat stage 1 output (Heat stage 3 for HP systems)
W1
Fan
Fan output
G
C1
Compressor stage 1 output
Y1
CO*
Heat stage 2 output for Standard HVAC systems
Changeover valve output for Heat Pump HVAC systems
W2
O
C2
Compressor stage 2 output
Y2
*
The CO output is set by the system type switch (SW1) setting. When set to Standard systems the output
becomes Heating Stage 2 (W2). When set to Heat Pump setting the output becomes the Changeover
(reversing) valve output (O).
System Status LED
The Control Unit has a Status LED on the circuit board that will normally
flash on and off slowly
as a
system heartbeat. The System Status LED can also show MRT/MOT states and X10 Communications.
Status LED MRT/MOT Indication
During the Minimum Run Time (MRT) period (default 6 minutes) after the beginning of a heating or cooling
call and during the Minimum Off Time (MOT) period after a call ends (also default 6 minutes), the system
status LED will
flash twice slowly
for each heartbeat. During the MOT period the compressor outputs are
locked out to provide short cycle protection.
Status LED X10 Signal Reception or Transmission Indication
When the TXB16 is first powered up, the status LED will come ON steady, indicating power and the unit is
running OK. When the X10 power line interface is connected
and an X10 signal is detected
, the LED will
start flashing slowly as the normal system heartbeat.
If the X10 signal is lost, the LED will stop flashing and be ON steady. If this occurs, check the following:
1. Check that the X10 Power Line Interface module is powered and its LED is on. If not check the
110VAC circuit to be sure it is not switched off.
2. Check that the modular cable is plugged in securely on the X10 PLI and the TX16B
3. Verify that the correct “reversing” type modular cable is installed if not the factory cable or it has
been changed before the problem occurred.
4. Replace module or cable as needed to restore X10 communications.
Any X10 Command Received.
When the control unit receives
any valid X10 Command
, the Status LED
will
flash twice
rapidly.
Note that the LED on the X10 PLI module will also flash when X10 commands are
detected.
X10 Command With Correct House Code Received.
If the X10 command received is also addressed
with the same house code as theTXB16 control unit, the status LED will
flash 4 times
rapidly. This is a
command for the TXB16!
X10 Command Transmitted.
When the TXB16 responds to a request for status or is set to AUTOSEND
mode, it will transmit X10 commands for temperatures, setpoints and modes. Whenever a X10 command
is transmitted by the control unit, the Status LED will
flash 4 times rapidly.
