37
Status LED
Status LED Description
Status LED Troubleshooting Information
POWER
(Green LED)
Module has power
Supply voltage is present at module terminals
TRIP
(Red LED)
Thermostat demand signal Y
is present, but compressor is
not running
•
Compressor protector is open
•
Check for high head pressure
•
Check compressor supply voltage
•
Outdoor unit power disconnect is open
•
Compressor circuit breaker or fuse(s) is open
•
Broken wire or connector is not making contact
•
Low pressure switch open if present in system
•
Compressor contactor has failed open
ALERT
Flash Code 1
(Yellow LED)
Long Run Time Compressor
is running extremely long run
cycles
•
Low refrigerant charge
•
Evaporator blower is not running
—
Check blower relay coil and contacts
—
Check blower motor capacitor
—
Check blower motor for failure or blockage
—
Check evaporator blower wiring and connectors
—
Check indoor blower control board
—
Check thermostat wiring for open circuit
•
Evaporator coil is frozen
—
Check for low suction pressure
—
Check for excessively low thermostat setting
—
Check evaporator airflow (coil blockages or return airfilter)
—
Check ductwork or registers for blockage
•
Faulty metering device
—
Check TXV bulb installation (size, location and contact)
—
Check if TXV/fixed orifice is stuck closed or defective
•
Condenser coil is dirty
•
Liquid line restriction (filter drier blocked if present in system)
•
Thermostat is malfunctioning
—
Solenoid plug not connected
—
Y2 not wired at Comfort Alert
—
Check thermostat sub-base or wiring for short circuit
—
Check thermostat installation (location, level)
•
Comfort Alert failure
ALERT
Flash Code 2
(Yellow LED)
System Pressure Trip
•
High head pressure
—
Check high pressure switch if present in system
—
Check if system is overcharged with refrigerant
—
Check for non-condensable in system
Discharge or suction
•
Condenser coil poor air circulation (dirty, blocked, damaged)
pressure out of limits
•
Condenser fan is not running
—
Check fan capacitor
—
Check fan wiring and connectors
—
Check fan motor for failure or blockage
compressor overloaded
•
Return air duct has substantial leakage
•
If low pressure switch present in system, check Flash Code 1
information
Table 15. LED Diagnostics
TROUBLESHOOTING
