Lennox iComfort SL18XC-01 Installer Setup Manual page 22

Table 1. Alert Codes and Troubleshooting
Alert
Priority Alert Text
Code
(Thermostat) The system has not been able
to turn on the cooling for more than 45
39 Critical
minutes. The system will go offline for 60
minutes and try again.
(Thermostat / Furnace / Air Handler / Out­
door Unit/ Equipment Interface Module /
105 Critical Damper Control Module) The (Thermostat,
furnace, air­handler or outdoor unit) has lost
communication with the rest of the system.
110 Critical (Furnace) The line voltage is too low.
(Furnace) The line power voltage wiring is
111 Critical
reversed.
(Furnace) The reporting device cannot find
112 Critical earth ground. The thermostat will shut down
the system.
113 Critical (Furnace) The line voltage is too high.
(Furnace / Air Handler/ / Equipment Interface
Module / Damper Control Module)) There is
114 Critical
a frequency/distortion problem with the
power to the (furnace or air­handler).
(Furnace / Air Handler) The 24VAC to the
(furnace or air­handler control board) is
115 Critical
lower than the required range of 18 to
30VAC.
(Damper Control Module) The secondary
115 Critical
24VAC damper control module is low.
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
Run the system in diagnostic mode and verify that it matches actual equipment operation.
Check for other alarms/codes that may be preventing the system from operating as ex­
pected.
Step 1: Check all cooling equipment to determine cause.
Step 2: Recycle power.
System will clear code when it detects condition has cleared.
Equipment is unable to communicate. This may indicate the existence of other alarms/
codes. In most cases errors are related to electrical noise. Make sure high voltage power
is separated from RSBus. Check for incorrectly wired and/or loose connections between
the Thermostat, indoor unit and outdoor unit. Check for a high voltage source of noise
close to the system. Generally, this is a self­recoverable error.
This alarm/code may appear during a brownout. Line voltage is below its designed operat­
ing value. Check and correct the power line voltage.
The unit is reporting that its power line and neutral are reversed. Turn off the power to the
system and correct the line power voltage wiring. System resumes normal operation 5
seconds after fault recovered.
Provide proper earth ground to the equipment. System resumes normal operation 5
seconds after fault recovered.
Line voltage high (voltage higher than nameplate rating). Provide power voltage within
proper range. System resumes normal operation 5 seconds after fault recovered.
This alarm/code may indicate transformer overloading. Check the voltage and line power
frequency. Check the generator operating frequency, if the system is running on back­up
power. Correct voltage and frequency problems. System resumes normal operation 5
seconds after fault recovered.
24­Volt Power Low (Range is 18 to 30 volts). Check and correct voltage. Check for addi­
tional power­robbing equipment connected to system. This alarm/code may require the
installation of an additional or larger VA transformer.
24­Volt Power Low (Range is 18 to 30 volts). Check and correct voltage. Check for addi­
tional power­robbing equipment connected to system. This alarm/code may require the
installation of an additional or larger VA transformer.
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