Lennox XP25-024-230-01 Installation And Service Procedure page 34

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 434 53 5 flashes
E 435 60 6 flashes
E 436 62 6 flashes
E 437 65 6 flashes
E 438 73 7 flashes
E 439 12 1 flash
®
thermostat.
Priority
Green LED
Outdoor control has lost
communications with the
inverter for greater than 3
minutes. Outdoor control
will stop all compressor de­
mands, recycle power to
Moderate /
3 flashes the inverter by de-energiz­
Critical
ing the contactor for 2
minutes. If this occurs 3
time in one thermostat call,
the outdoor unit will locked
out and display a critical
code.
Moderate /
OFF Inverter internal error.
Critical
Inverter heat sink temperat­
ure exceeded limit. Occurs
when the heat sink temper­
ature exceeds the inverter
limit. Inverter issues code
13 first, then slows down to
allow the heat sink to cool. If
Moderate /
2 flashes temperature remains high,
Critical
outdoor unit stops (com­
pressor and fan). Anti-short
cycle is initiated. If condition
occurs 5 times within an
hour, system is locked out.
To clear, disconnect power
to outdoor unit and restart.
Heat sink temperature
sensor fault has occurred
Moderate /
5 flashes (temperature less than 4ºF
Critical
or greater than 264ºF after
10 minutes of operation)
The inverter has detected a
PFC over current condi­
tion. This would be caused
by a high load condition,
high pressure, or outdoor
fan failure. Outdoor control
will display the code when
the inverter has the error.
Moderate /
3 flashes After 3 minutes, the inverter
Critical
will reset and the com­
pressor will turn on again.
If it happens 10 times with­
in a 60 minute rolling time
period, the OD control will
lock out operation of the
outdoor unit and display a
critical code.
Compressor slowdown due
2 flashes Moderate
to high input current.
Alarm Description
Issues:
(1) Loose electrical connections.
(2) Interruption of main power to inverter.
Corrective Actions:
(1) Check all electrical connections.
(2) Check for proper main power to inverter.
When this error occurs, the outdoor control cycles
power to the inverter by opening the contactor for two
minutes. Check that the EEPROM is properly seated.
After power is cycled to the inverter 3 times, the out­
door unit is locked out
Issue: Feedback from supplier tear down of inverter in­
dicates that the screws that hold the inverter to the invert­
er board were loose causing poor contact between these
two components.
Corrective Action: Tighten screws that hold the heat
sink to the inverter control board.
NOTE: Wait five minutes to all capacitor to discharge be­
fore checking screws.
Occurs when the temperature sensor detects a temperat­
ure less than 0.4ºF or greater than 264ºF after 10 minutes
of operation. If condition is detected, outdoor unit will stop
(compressor and fan). Anti­short cycle is initiated. If con­
dition occurs 5 times within an hour, system will lock out.
To clear disconnect power to outdoor unit and restart. If
.
problem persists, replace inverter.
Issue: Possible issue is system running at high pres­
sures. Check for high pressure trips or other alert codes in
room thermostat and outdoor control.
Input current is approaching a high limit. Compressor
speed automatically slows. The control continues send­
ing the inverter speed demanded by the thermostat. The
control sets indoor CFM and outdoor RPM to values ac­
cording to demand percentage rather than the actual Hz.
Alarm is automatically cleared.
Page 34
Possible Causes and Clearing Alarm
.
XP25