Status
Status LED
LED
Description
Green
Module has
"POWER"
power
Thermostat
demand signal
Red "TRIP"
Y is present, but
compressor is not
running
Long Run Time
Yellow "ALERT"
Compressor is
Flash Code 1
running extremely
long run cycles
System
Pressure Trip
- Discharge or
Yellow "ALERT"
suction pressure
Flash Code 2
out of limits or
compressor
overloaded
TROUBLESHOOTING
Status LED Troubleshooting Information
Supply voltage is present at module terminals
•
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
•
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 airfl ow (coil blockages or return airfi lter)
—
Check ductwork or registers for blockage
•
Faulty metering device
—
Check TXV bulb installation (size, location and contact)
—
Check if TXV/fi xed orifi ce is stuck closed or defective
•
Condenser coil is dirty
•
Liquid line restriction (fi lter 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
•
High head pressure
—
Check high pressure switch if present in system
—
Check if system is overcharged with refrigerant
—
Check for non-condensable in system
•
Condenser coil poor air circulation (dirty, blocked, damaged)
•
Condenser fan is not running
—
Check fan capacitor
—
Check fan wiring and connectors
—
Check fan motor for failure or blockage
•
Return air duct has substantial leakage
•
If low pressure switch present in system, check Flash Code
1 information
Table 4. LED Diagnostics
15