Lennox XP25-024-230-01 Installation And Service Procedure page 31

Table 6. 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/dehumidification).
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 iComfort Wi-Fi
Inverter LED Flash
Code (number of
Alert Inverter
flashes)
Code
Codes
Red LED
E 345 N/A N/A
E 409 N/A N/A
E 410 N/A N/A
E 411 N/A N/A
E 412 N/A N/A
E 413 N/A N/A
®
thermostat.
Priority
Green LED
Heat Pump or Air Condition­
er Alert Code - The "O" re­
lay on the outdoor board
has failed. Either the pilot
relay contacts did not close,
N/A Critical
the relay coil did not ener­
gize or the circuit that con­
firms this operational se­
quence is not sensing prop­
erly.
Outdoor control secondary
N/A Moderate
voltage is 18VAC or less.
The outdoor unit low pres­
N/A Moderate
sure switch has closed.
The low pressure switch has
opened 5 times within one
N/A Critical
hour. As a result, the out­
door unit is locked out
The outdoor unit high pres­
N/A Moderate
sure switch has opened.
The high pressure switch
has opened 5 times within
N/A Critical
one hour. As a result, the
outdoor unit is locked out
Alarm Description
Issue: Broken R50 will make the control board think
reversing valve output is always off regardless of state
of relay. (Supplier issue - We have found our functional
test fixture can bend over MOV2 and crush it into
R50.There are cut-outs in the plate of the fixture to let
the two relays pass through as the plate with pogo pins
is moved to the board to make contact with the termin­
als. There is a pocket milled out in the plate to let
MOV2 pass, but if MOV2 is not straight up, it could
catch the plate outside the pocket and be bent down to
the board. Lennox is enlarging the cut-outs in the plate
so MOV2 will clear the fixture. Corrective action com­
pleted on August 29,2013.
Corrective Actions: Short term fix: Converted the sys­
tem back to a 24 volt system to get unit operating. Long
term: Replace outdoor control.
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
shutdown. The low pressure switch opens at 25PSIG
and closes at 40PSIG. Confirm that the system is prop­
erly 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 switch opens or after a power
reset.
Low pressure switch error count reached 5 strikes. The
low pressure switch opens 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 refriger­
.
ant 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 zon­
ing 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 zon­
ing system, zone CFM may be set too low.
Page 31
Possible Causes and Clearing Alarm
XP25