Lennox XP25-024-230-01 Installation And Service Procedure page 82

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 434 53 5 flashes
E 435 60 6 flashes
E 436 62 6 flashes
E 437 65 6 flashes
E 438 73 7 flashes
®
thermostat.
Priority
Green LED
Moderate /
3 flashes
Critical
Moderate /
OFF
Critical
Moderate /
2 flashes
Critical
Moderate /
5 flashes
Critical
Moderate /
3 flashes
Critical
Page 82
Alarm Description
Outdoor control has lost
communications with the
inverter for greater than
Issues:
3 minutes. Outdoor con­
trol will stop all com­
(1) Loose electrical connections.
pressor demands, re­
(2) Interruption of main power to inverter.
cycle power to the invert­
er by de-energizing the
Corrective Actions:
contactor for 2 minutes.
(1) Check all electrical connections.
If this occurs 3 time in
one thermostat call, the
(2) Check for proper main power to inverter.
outdoor unit will locked
out and display a critical
code.
When this error occurs, the outdoor control cycles
power to the inverter by opening the contactor for
Inverter internal error. 2 minutes. Check that the EEPROM is properly
seated. After power is cycled to the inverter 3
times, the outdoor unit is locked out
Inverter heat sink tem­
perature exceeded limit.
Occurs when the heat
sink temperature ex­
ceeds the inverter limit.
Issue: Feedback from supplier tear down of inverter
Inverter issues code 13
indicates that the screws that hold the inverter to the
first, then slows down to
inverter board were loose causing poor contact
allow the heat sink to
between these two components.
cool. If temperature re­
mains high, outdoor unit
Corrective Action: Tighten screws that hold the
stops (compressor and
heat sink to the inverter control board.
fan). Anti-short cycle is
NOTE: Wait five minutes to all capacitor to dis­
initiated. If condition oc­
charge before checking screws.
curs 5 times within an
hour, system is locked
out. To clear, disconnect
power to outdoor unit
and restart.
This occurs when the temperature sensor detects
Heat sink temperature
a temperature less than 0.4ºF or greater than
sensor fault has occurred
264ºF after 10 minutes of operation. If condition is
(temperature less than 4 detected, outdoor unit compressor and fan stop.
Anti­short cycle is initiated. If condition occurs 5
ºF or greater than 264ºF
times within an hour, system is locked out. To clear
after 10 minutes of opera­
disconnect power to outdoor unit and restart. If
tion)
.
problem persists, replace inverter.
The inverter has detec­
ted a PFC over current
condition. This would be
caused by a high load
condition, high pressure,
or outdoor fan fail­
ure. Outdoor control will
display the code when
the inverter has the er­
Issue: Possible issue is system running at high
ror. After 3 minutes, the
pressures. Check for high pressure trips or other
alert codes in room thermostat and outdoor control.
inverter will reset and
the compressor will turn
on again. If it happens
10 times within a 60
minute rolling time peri­
od, the OD control will
lock out operation of the
outdoor unit and display
a critical code.
Possible Causes and Clearing Alarm
.
XP25