Nordyne 16 SEER series Installation Instructions Manual page 18

Status led Status led description
POWER
Module has power
(Green LED)
Thermostat demand signal Y
TRIP
is present, but compressor is
(Red LED)
not running
ALERT Long Run Time
Flash Code 1 Compressor is running
(Yellow LED) extremely long run cycles
System Pressure Trip
Discharge or suction
ALERT
Flash Code 2
(Yellow LED)
Pressure out of limits
Compressor overloaded
ALERT
Short Cycling / Compressor is
Flash Code 3
running only briefly
(Yellow LED)
ALERT
Flash Code 4 Locked Rotor
(Yellow LED)
ALERT
Flash Code 5 Open Circuit
(Yellow LED)
18
comfort alert trouBleShooting
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 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
• 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
• Thermostat demand signal is intermittent
• Low line voltage (contact utility if voltage at disconnect is low)
• Excessive liquid refrigerant in compressor
• Compressor bearings are seized
• Run capacitor has failed
• Low line voltage (contact utitlity if voltage at disconnect is low)
• Check wiring connections
• Excessive liquid refrigerant in compressor
• Compressor bearings are seized
• Measure compressor oil level
• Outdoor unit power disconnect is open
• Compressor circuit breaker or fuse(s) is open
• Compressor contactor has failed open
— Check compressor contactor wiring and connectors
— Check for compressor contactor failure (burned, pitted or open)
— Check wiring and connectors between supply and compressor
— Check for low pilot voltage at compressor contactor coil
— High pressure switch is open and requires manual reset
• Open circuit in compressor supply wiring or connections
• Unusually long compressor protector reset time due to extreme ambient temperature
• Compressor windings are damaged
— Check compressor motor winding resistance
table 3. led diagnostics
Status led troubleshooting information