Reznor JT4BD Unit Installation Manual - Manual (Page 26)

26
coMFort alErt trouBlESHootIng
table 17. lED Diagnostics
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
ALERT
Flash Code 3
(Yellow LED)
Short Cycling / Compressor is
running only briefly
• 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
ALERT
Flash Code 4
(Yellow LED)
Locked Rotor
• 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
ALERT
Flash Code 5
(Yellow LED)
Open Circuit
• 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