Lennox SL280UHNV Series

Page 9
TABLE 5
Integrated Diagnostic Codes/Status of Equipment I.
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
.
Idle mode (Decimal blinks at 1 Hertz -- 0.5 second ON, 0.5 second OFF).
A
Cubic feet per minute (cfm) setting for indoor blower (1 second ON, 0.5
second OFF) / cfm setting for current mode displayed.
C
Cooling stage (1 second ON, 0.5 second OFF) / 1 or 2 displayed / Pause
/ cfm setting displayed / Pause / Repeat codes).
d
Dehumidification mode (1 second ON) / 1 second OFF) / cfm setting dis
played / Pause / Repeat Codes).
h
Heat pump stage (1 second ON, 0.5 second OFF) / % of input rate dis
played / Pause / cfm setting / Pause / Repeat codes.
H
Gas Heat Stage (1 second ON, 0.5 second OFF) / 1 or 2 displayed /
Pause / cfm
setting displayed / Pause / Repeat codes. Blinking during ignition.
dF
Defrost mode.
U
Discharge Air Temperature
E 105
Device communication problem - No other devices on RS BUS (Commu
nication
system).
Equipment is unable to communicate. Indicates
numerous message errors. In most cases errors are
related to electrical noise. Make sure high voltage
power is separated from RSBus. Check for mis-
wired and/or loose connections between the stat,
indoor unit and outdoor unit. Check for a high volt
age source of noise close to the system. Fault
clears after communication is restored.
E 110
Low line voltage. Line Voltage Low (Voltage lower than nameplate
rating). Check power line voltage and correct. Alarm
clears 5 seconds after fault recovered.
E 111
Line voltage polarity reversed. Reverse line power voltage wiring. System resumes
normal operation 5 seconds after fault recovered.
E 112
Ground not detected System shuts down. Provide proper earth ground.
System resumes normal operation 5 seconds after
fault recovered.
E 113
High line voltage. Line Voltage High (Voltage higher than nameplate
rating). Provide power voltage within proper range.
System resumes normal operation 5 seconds after
fault recovered.
E 114
Line voltage frequency out-of-range. No 60 Hertz Power. Check voltage and line power
frequency. Correct voltage and frequency problems.
System resumes normal operation 5 seconds after
fault recovered.
E 115
Low 24V - Control will restart if the error recovers. 24-Volt Power Low (Range is 18 to 30 volts). Check
and correct voltage. Check for additional power-rob
bing equipment connected to system. May require
installation of larger VA transformer to be installed
in furnace / air handler. Clears after fault recovered.
E 116
High 24V. 24 Volt Power High (Range is 18 to 30 volts). Check
and correct voltage. Check for proper line voltage
(120V, 240V, etc.) to equipment. Clears when con
trol senses proper voltage.
E 117
Poor ground detected (Warning only) Provide proper grounding for unit. Check for proper
earth ground to the system. Warning only will clear
30 seconds after fault recovered.
E 120
Unresponsive device. Communication only. Usually caused by delay in outdoor unit responding
to indoor unit poling. Recycle power. Check all wir
ing connections. Cleared after unresponsive device
responds to any inquiry.