Lennox iComfort SL18XC-01 Installer Setup Manual page 30

Table 1. Alert Codes and Troubleshooting
Alert
Priority Alert Text
Code
(Outdoor Unit) The required amount of cur­
406 Critical rent is not passing through the start current
transformer.
(Outdoor Unit) The required amount of cur­
407 Critical rent is not passing through run current trans­
former.
(Outdoor Unit) The compressor is running
408 Critical
continuously.
(Furnace / Air Handler / Outdoor Unit) The
secondary voltage for the (furnace, air­hand­
ler or outdoor unit) has fallen below 18VAC.
409 Moderate
If this continues for 10 minutes, the thermo­
stat will turn off the (furnace, air­handler or
outdoor unit).
(Outdoor Unit) The outdoor unit pressure is
410 Moderate
below the required limit.
(Outdoor Unit) The low pressure switch has
opened 5 times during a single demand. As
411 Critical
a result, the thermostat has shutdown the
outdoor unit.
(Outdoor Unit) The outdoor unit pressure is
412 Moderate above the required limit. The system will
shut down.
(Outdoor Unit) The high pressure switch has
opened 5 times during a single demand. As
413 Critical
a result, the thermostat has shutdown the
outdoor unit.
(Outdoor Unit) The discharge line temperat­
414 Critical ure is higher than the recommended upper
limit of 279ºF.
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
Required amount of current is not passing through Start current transformer. Clears the
error after current is sensed in START sensor, or after power reset.
Required amount of current is not passing through the RUN current transformer. Clears
the error after current is sensed in the RUN sensor, or 1 normal compressor run cycle, or
after power reset
Compressor runs continuously. Clears the error after 1 normal compressor run cycle or
after power reset.
Secondary voltage is below 18VAC. After 10 minutes, operation is discontinued. Clears the
code after voltage is higher than 20VAC for two seconds or after power reset.
Low pressure switch opens at at a specific pressure (system shuts down) and
closes at a specific pressure (system restarts). For specific unit low pressure
values, see the applicable unit documentation.
Open low pressure switch error count reached five strikes. Check system charge using
approach and sub cooling temperatures. Reset by putting outdoor unit control in test mode
or resetting low voltage power.
Unit pressure is above the upper limit. System is shut down. Confirm that the system is
properly charged with refrigerant. Check condenser fan motor, TXV, indoor unit blower
motor, stuck reversing valve or clogged refrigerant filter. Confirm that the outdoor unit is
clean. The alarm clears after the pressure switch closes or a power reset
Open high pressure switch error count reached 5 strikes. Check system charge using
approach and sub cooling temperatures. Check outdoor fan operation. Check for dirt or
debris blocking air flow to outdoor unit. Reset by putting outdoor unit control in test mode
or resetting low voltage power.
Discharge line temperature is > 279ºF. Make sure coil is clean and airflow unobstructed in
and out of condenser. Check system operating pressures and compare to unit charging
charts in installation manual. Clears after discharge temperature is < 225ºF.
30