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XP25
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
®
thermostat.
Alert
Codes
Inverter
Code
Inverter LED Flash
Code (number of
flashes)
Priority
Alarm Description
Possible Causes and Clearing Alarm
Red LED
Green LED
E 416
N/A
N/A
N/A
Moderate
/ Critical
The outdoor coil sensor has
malfunctioned. As a result
the outdoor unit control will
not perform defrost.
Coil sensor being detected open or shorted, or temper
ature is out of coil sensor range. Outdoor unit control
will not perform demand or time/temperature defrost
operation. System is still able heat and cool. Check the
resistance of the coil sensor and compare to temperat
ure resistance chart. Replace coil sensor if needed.
The alarm clears when outdoor unit control detects
proper coil sensor readings or after a power reset.
E 422
N/A
N/A
N/A
Moderate
Compressor top cap switch
exceeding thermal limit.
Issue
: One of the wires from the top cap switch had
pulled off one of the TP terminals on the outdoor con
trol board.
Corrective Action
: Reconnected wire onto top cap
terminal.
E 423
40
4 flashes
OFF
Moderate
/ Critical
The inverter has detected a
circuit problem
.
Control locks out after 10 strikes within an hour. To
clear, disconnect power to outdoor unit and restart.
E 424
N/A
N/A
N/A
Moderate
The liquid line temperature
sensor has malfunctioned.
In normal operation, after outdoor control recognizes
sensors, the alarm is sent if valid temperature reading
is lost. Compare liquid line sensor resistance to tem
perature/resistance charts in unit installation instruc
tions. Replace sensor pack if necessary. At the begin
ning of (any) configuration, furnace or airhandler con
trol detects the presence of the sensor(s). If detected
(reading in range), appropriate feature is shown in the
iComfort WiFi
®
thermostat About screen. The alarm /
fault clears upon configuration, or when normal values
are sensed.
E 425
N/A
N/A
N/A
Minor
Outdoor control has in
creased minimum com
pressor speed to allow for
proper oil return due to low
ambient temperature.
NOTE -
Minimum speed adjustments
begin at 45°F and increase to
100% minimum at 17°F.
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.
E 426
N/A
N/A
N/A
Critical
Excessive inverter alarms
After ten faults within one hour, control is locked out,
indicating poor system operation. Review history of
alarms to resolve system setup. Check condenser fan
motor, TXV, indoor unit blower motor, over-charge, un
dercharge, or clogged refrigerant filter.
To clear error, disconnect power to outdoor unit and
restart. Inverter alarms 12 to 14 and 53 do not count
toward this lock out condition.
E 427
21
2 flashes
1 flash
Moderate
/ Critical
The inverter has detected a DC peak fault condition. If condition (55A or higher) is
detected, outdoor unit compressor and fan stop. Anti-short cycle is initiated. If peak
current (55A or higher) occurs 10 times within an hour, system is locked out. Indicates
high pressure, condenser fan failure, locked compressor rotor or overcharge. To clear,
disconnect power to outdoor unit and restart.
E 428
22
2 flashes
2 flashes
Moderate
/ Critical
The inverter has detected a
high main input current con
dition
.
If condition is detected, is detected, outdoor unit com
pressor and fan stop. Antishort cycle is initiated. If
condition occurs 5 times within an hour, system is
locked out.
Indicates high pressure, condenser fan failure or over
charge.
To clear, disconnect power to outdoor unit and restart.
