5 Troubleshooting
5.1 Testing the Unit
Once everything is correctly installed, turn the power and:
1. The Green LED on the interface board should be blinking once every two seconds.
2. The Orange LED on the interface board should be blinking once every two seconds.
3. The communicating thermostat will find the heat pump.
4. Set the thermostat to “COOL” mode and adjust the set point to a lower value than the actual
room temperature.
5. The Blue LED on the interface board should turn on and both the furnace and the outdoor unit
should start within 5 minutes.
5.2 LED Codes
Green LED
There are two green LEDs.
The upper green LED should blink steadily, otherwise it indicates an error code from the outdoor unit.
The lower green LED, along with the orange LED next to it, will indicate the current error code (see
table on next page).
Orange LED
The orange LED, along with the green LED next to it, will indicate the current error code (see table
on next page).
Yellow LED
In communicating mode, the yellow LED should be blinking by short bursts. If not, there is a
communication issue with the furnace. RJ-11 cable and wires 1 and 2 should be checked.
In legacy mode (24V), this LED should stay off.
Blue LED
The blue LED will turn on when there is a call for cooling from the thermostat.
Red LED
The red LED will turn on when there is a call for heating from the thermostat.
White LED
The white LED will turn on when there is a call for ERV fan or dehumidification. In communicating
mode, this LED will blink when there is a dehumidifiaction call.
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