Lennox XP25-024-230-01 Installation And Service Procedure page 83

Table 21. 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
Alert
(number of flashes)
Code
Codes
Red LED
E 439 12 1 flash
E 440 13 1 flash
E 441 14 1 flash
®
thermostat.
Priority
Green LED
2 flashes Moderate
3 flashes Moderate
4 flashes Moderate
Page 83
Alarm Description
Input current is approaching a high limit. Com­
pressor speed will automatically slow down. The
Compressor slowdown
control continues sending the inverter speed de­
due to high input cur­ manded by the thermostat. The control will set in­
rent.
door CFM and outdoor RPM to values according
to demand percentage rather than the actual Hz.
Alarm is automatically clear. See E428.
Heat sink temperature is
approaching limit. The
Issue: Feedback from supplier tear down of invert­
compressor speed auto­
er indicates that the screws that hold the inverter to
matically slows to re­
the inverter board were loose causing poor contact
duce heat sink temperat­
between these two components.
ure. The control sets in­
door CFM and outdoor
Corrective action: Tighten screws that hold the
RPM to values accord­
heat sink to the inverter control board.
ing to demand percent­
NOTE: Wait 5 minutes to all capacitor to discharge
age rather than the actu­
before checking screws.
al Hz. Alarm is automat­
ically cleared.
Compressor slowdown
due to high compressor
current. Compressor
current is approaching
limit. The compressor
speed automatically Issue: Possible issue is system running at high
slows. The control sets pressures. Check for high pressure trips or other
indoor CFM and outdoor alert codes in room thermostat and outdoor control.
RPM to values accord­
ing to demand percent­
age rather than the actu­
al Hz. Alarm is automat­
ically cleared..
Possible Causes and Clearing Alarm
XP25