Lennox iComfort SL18XC-01 Installer Setup Manual page 34

Table 1. Alert Codes and Troubleshooting
Alert
Priority Alert Text
Code
Compressor slowdown due to high input cur­
439 Moderate
rent.
Compressor slowdown due to high heat­sink
440 Moderate
temperature.
Compressor slowdown due to high com­
441 Moderate
pressor current.
The top cap switch has opened 5 times with­
442 Critical in one hour. As a result, the outdoor unit is
locked out.
443 Critical Incorrect appliance unit size code selected.
Moderate /
530 Low Damper 24VAC Voltage
Critical
Zoning Pressure Switch Opened (high pres­
532 Moderate
sure)
Moderate /
542 Zone 1 Temperature Sensor Problem
Critical
Moderate /
543 Zone 2 Temperature Sensor Problem
Critical
Moderate /
544 Zone 3 Temperature Sensor Problem
Critical
Moderate /
545 Zone 4 Temperature Sensor Problem
Critical
507341-02
Critical alerts are displayed on Home (user) screen, in the Homeowner alert button, and in
the Installer alert button. Minor and Moderate alerts are found only in the Installer alert
button.
Steps to clear
Input current is approaching a high limit. Compressor speed will automatically slow down.
The control continues sending the inverter speed demanded by the thermostat. The con­
trol will set indoor CFM and outdoor RPM to values according to demand percentage
rather than the actual Hz. Alarm is automatically clear.
Heat sink temperature is approaching limit. The compressor speed will automatically slow
down to reduce heat­sink temperature. The control will set indoor CFM and outdoor RPM
to values according to demand percentage rather than the actual Hz. Alarm is automatic­
ally cleared.
Compressor current is approaching high limit. The compressor speed will automatically
slow down. The control will set indoor CFM and outdoor RPM to values according to de­
mand percentage rather than the actual Hz. Alarm is automatically cleared.
When compressor thermal protection sensor opens 5 times within 1 hour. Outdoor unit will
stop. To clear, disconnect power to outdoor unit and restart.
Check for proper configuring under unit size codes for outdoor unit on configuration guide
or in installation instructions. If replacing inverter, verify inverter model matches unit size.
The alarm/fault clears after the correct match is detected following a reset. Remove the
thermostat from the system while applying power and reprogramming.
• Damper Supply voltage is < 18VAC.
• Maintain non­zone mode for 5 minutes after alarm clears.
Compressor pressure is above the specified limit. Compressor is turned off. Zoning will be
restored once the high pressure switch closes.
Invalid temperature reading, Open or short sensor detected. System is restored 30
seconds after fault is recovered.
Invalid temperature reading, Open or short sensor detected. System is restored 30
seconds after fault is recovered.
Invalid temperature reading, Open or short sensor detected. System is restored 30
seconds after fault is recovered.
Invalid temperature reading, Open or short sensor detected. System is restored 30
seconds after fault is recovered.
34