Table of Contents
Advertisement
Status LED Description
Status LED
Green "POWER"
Module has power
Red "TRIP"
Thermostat demand signal
Y is present, but the
compressor is not
running
Yellow "ALERT"
Long Run Time
Flash Code 1
Compressor is
running extremely
long run cycles
Yellow "ALERT"
System Pressure Trip
Flash Code 2
Discharge or suction
pressure out of limits or
compressor overloaded
Yellow "ALERT"
Short Cycling
Flash Code 3
Compressor is running
only briefly
Yellow "ALERT"
Locked Rotor
Flash Code 4
Yellow "ALERT"
Open Circuit
Flash Code 5
Yellow "ALERT"
Open Start Circuit
Flash Code 6
Current only in run circuit
Yellow "ALERT"
Open Run Circuit
Flash Code 7
Current only in start circuit
Yellow "ALERT"
Welded Contactor
Flash Code 8
Compressor always runs
Yellow "ALERT"
Low Voltage
Flash Code 9
Control circuit < 17VAC
•
Flash Code number corresponds to a number of LED flashes, followed by a pause and then repeated.
•
TRIP and ALERT LEDs flashing at same time means control circuit voltage is too low for operation.
Table 1. Interpreting the Diagnostic LEDS
Status LED Troubleshooting Information
Supply voltage is present at module terminals
1. Compressor protector is open
2. Outdoor unit power disconnect is open
3. Compressor circuit breaker or fuse(s) is open
4. Broken wire or connector is not making contact
5. Low pressure switch open if present in system
6. Compressor contactor has failed open
1. Low refrigerant charge
2. Evaporator blower is not running
3. Evaporator coil is frozen
4. Faulty metering device
5. Condenser coil is dirty
6. Liquid line restriction (filter drier blocked if present in system)
7. Thermostat is malfunctioning
8. Comfort Alert Failure
1. High head pressure
2. Condenser coil poor air circulation (dirty, blocked, damaged)
3. Condenser fan is not running
4. Return air duct has substantial leakage
5. If low pressure switch present in system, check Flash
Code 1 information
1. Thermostat demand signal is intermittent
2. Time delay relay or control board defective
3. If high pressure switch present go to Flash Code 2 information
4. If low pressure switch present go to Flash Code 1 information
1. Run capacitor has failed
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections
3. Excessive liquid refrigerant in compressor
4. Compressor bearings are seized
• Measure compressor oil level
1. Outdoor unit power disconnect is open
2. Compressor circuit breaker or fuse(s) is open
3. 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
4. High pressure switch is open and requires manual reset
5. Open circuit in compressor supply wiring or connections
6. Unusually long compressor protector reset time due to
extreme ambient temperature
7. Compressor windings are damaged
• Check compressor motor winding resistance
1. Run capacitor has failed
2. Open circuit in compressor start wiring or connections
• Check wiring and connectors between supply and the
compressor "S" terminal
3. Compressor start winding is damaged
• Check compressor motor winding resistance
1. Open circuit in compressor run wiring or connections
• Check wiring and connectors between supply and the
compressor "R" terminal
2. Compressor run winding is damaged
• Check compressor motor winding resistance
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
1. Control circuit transformer is overloaded
2. Low line voltage (contact utility if voltage at disconnect is low)
• Check wiring connections
9
Hide quick links:
Advertisement
Table of Contents
