Lennox EL23XCV Series Manual page 36

TABLE 7. Outdoor Control 7-Segment Display Alert Codes and Inverter LED Flash Codes
NOTE – System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or defrost/dehumidifi-
cation). Only the latest active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system status codes are
displayed. Alert codes are also displayed on the S30/S40 thermostat.
Inverter LED Flash Code
Alert Inverter
(number of flashes)
Codes Code
Red LED
E183 N/A N/A
E345 N/A N/A
E409 N/A N/A
E410 N/A N/A
E411 N/A N/A
E412 N/A N/A
E413 N/A N/A
E416 N/A N/A
E422 N/A N/A
E423 40 4 flashes
E424 N/A N/A
E425 N/A N/A
Priority
Green LED
Service Liquid pressure transducer is
N/A
Soon out of range.
Heat Pump or Air Conditioner
N/A Critical Alert Code - The "O" relay on
the outdoor board has failed.
Outdoor control secondary
N/A Moderate
voltage is 18VAC or less.
The outdoor unit cycled off due
N/A Moderate
to low suction pressure.
The low pressure fault has
occurred 5 times within one
N/A Critical
hour. As a result, the outdoor
unit is locked out.
The outdoor unit high pressure
N/A Moderate
switch has opened.
The high pressure switch has
opened 5 times within one hour.
N/A Critical
As a result, the outdoor unit is
locked out.
Moderate The outdoor coil sensor has
N/A
/ Critical malfunctioned.
Compressor top cap switch
N/A Moderate
exceeding thermal limit.
Moderate The inverter has detected a
OFF
/ Critical circuit problem.
The liquid line temperature
N/A Moderate
sensor has malfunctioned.
Outdoor control has increased
minimum compressor speed to
allow for proper oil return due to
N/A Minor low ambient temperature. NOTE
- Minimum speed adjustments
begin at 45°F and increase to
100% minimum at 17°F.
Alarm Description
The signal should be between 0.5 VDC and 4.5 VDC between
Blue and Black. The error code will be cleared when the proper
signal is provided. Systems controlled by a conventional 24VAC
heat pump thermostat will operate in stage mode.
Either the pilot relay contacts did not close, the relay coil did not
energize the circuit that confirms this operational sequence is not
sensing properly.
Secondary voltage is below 18VAC. After 10 minutes, operation is
discontinued. Check the indoor line voltage and transformer output
voltage. The alarm clears after the voltage is higher than 20VAC
for 2 seconds or after a power reset.
Unit pressure is below the lower limit. The system is shut down.
The suction pressure transducer emulates a low pressure switch,
the unit does not have a low pressure switch. The cut-out is set at
40 PSIG and the cut-in set at 90 PSIG. Confirm that the system is
properly charged with refrigerant. Check TXV, indoor unit blower
motor, dirty filters or clogged refrigerant filter. Confirm that the
evaporator coil is clean. The alarm clears after the pressure rises
above 90 PSIG.
Low pressure fault error count reached 5 strikes. The low pressure
cut-out is at 40PSIG and resets at 90PSIG. Confirm that the
system is properly charged with refrigerant. Check for clogged
TXV, blockage to indoor unit blower motor, dirty filters or clogged
refrigerant filter. Confirm that the evaporator coil is clean. The
alarm clears after a power reset.
Unit pressure is above the upper limit. System is shut down. The
high pressure switch opens at 590PSIG and closes at 418PSIG.
Confirm that the system is properly charged with refrigerant.
Check for clogged TXV, blockage to indoor unit blower motor,
clogged refrigerant filter. Confirm that the outdoor unit is clean.
The alarm clears after the pressure switch closes or a power reset.
For heating, indoor CFM may be set too low. For zoning system,
zone CFM may be set too low.
Open high pressure switch error count reached 5 strikes. System
is shut down. The high pressure switch for HFC410A opens at
590PSIG and closes at 418PSIG. Confirm that the system is
properly charged with refrigerant. Check condenser fan motor,
for clogged TXV, for blockage to indoor unit blower motor, for
stuck reversing valve or clogged refrigerant filter. Confirm that the
outdoor unit is clean. The alarm clears after a power reset.
For heating, indoor CFM may be set too low. For zoning system,
zone CFM may be set too low.
EL23XCV has a fixed 10K ohm resistor installed on the harness
connector between pins 5 & 6. Check connections on pins 5 & 6
and check for resistance of 10K ohms. Error code will occur on
open or shorted circuit
The top of the compressor is hot. Refrigerant charge may be low,
or low mass flow of refrigerant. Check TXV, clogged filter drier,
condenser fan motor, indoor blower motor, confirm indoor coil is
clean.
Control locks out after 10 strikes within an hour. To clear,
disconnect power to the indoor unit (24VAC power source to the
outdoor control) which will power off the outdoor control and will
open the outdoor unit contactor, which interrupts power to the
inverter and then re-apply power.
Check connections between pin 3 and 4 of the four pin liquid/
suction temperature plug on the bottom left corner of the control.
Check resistance of resistor. Nominal 10K Ohms at 77F. Error
code occurs if sensor is open or shorted.
Outdoor ambient temperature is below system limit. Control
attempts to run at lowest allowed compressor speed to allow
for proper oil return. Automatically clears when outdoor ambient
temperature rises above limit for more than 5 minutes.
Page 36
Possible Causes and Clearing Alarm