Lennox XC21 Series Unit Information page 38

System fault and lockout LED (DS11 / DS14) alarm codes takes precedence over system status LED codes (cooling, heating stages or
defrost/dehumidification). Only the latest active LED fault or lockout alarm code if present will be displayed. If no fault or lockout codes are active, then
system status LEDs are routinely displayed. See notes 1 and 2 in table below for duration of fast / slow flashes and pause.
Air Conditioner
Control LEDs
Thermostat Thermostat Thermostat
DS11 DS11 DS14 DS14
Green Green Red Red
Moderate Alert
Off
Slow flash
Critical Alert
Off On
Moderate Alert
Slow flash Off
Critical Alert
On Off
Moderate Alert
Slow flash On
Critical Alert
Fast flash On
Critical Alert
OFF Fast flash
Simultaneous Fast flash
then Pause
Fast simultaneous flashing of DS11, DS13,
DS14 and DS15
1. Pause duration is two (2) seconds.
2. Fast flash duration is 1/2 second. Slow flash duration is one (1) second.
Table 10. Compressor Fault and Lockout LED Codes and Related icomfort Toucht Thermostat Alert Codes
NOTE See notes 1 and 2 in table below for duration of fast / slow flashes and pause.
Air Conditioner
icomfort
Control LEDs
Toucht
DS15 DS13 Thermostat
Yellow Red
Display
Moderate/
Off On Critical Alert
400
XC21
icomfort icomfort icomfort
Toucht Toucht Toucht
Condition Condition Condition
Display Display Display
Low pressure
Code 410 fault
Low pressure
Code 411 switch lockout
High pressure
Code 412 fault
High pressure
Code 413 switch lockout
Discharge line
Code 414 temperature fault
Discharge line
temperature
Code 415
lockout
Moderate /
Discharge sensor
fault
Code 417
Second−stage
None
heat lock−in
OEM mode
Possible
Condition
Cause(s)
Thermostat
Compressor
demand signal
3
internal Y1 is present, but
overload trip compressor not
running
Possible Possible Possible
Cause(s) Cause(s) Cause(s)
1
Restricted air
flow over indoor
or outdoor coil.
2
Improper
1
Remove any blockages or restrictions from coils and/or
refrigerant
fans. Check indoor and outdoor fan motor for proper
charge in
current draws.
system.
2
Check system charge using approach and subcooling
3
Improper
temperatures.
metering device
3
installed or Check system operating pressures and compare to unit
incorrect charging charts.
operation of
4
Make sure all pressure switches and sensors have
metering
secure connections to system to prevent refrigerant
device.
leaks or errors in pressure and temperature
4
Incorrect or measurements.
improper
sensor location
or connection to
system.
This code detects high discharge temperatures. If the discharge line
temperature exceeds a temperature of 279ºF (137ºC) during compressor
operation, the control will de−energize the compressor contactor output (and
the defrost output if active). The compressor will remain off until the discharge
temperature has dropped below 225ºF (107ºC).
The A175 control detects open or short sensor or out of temperature sensor
range. This fault is detected by allowing the unit to run for 90 seconds before
checking sensor resistance. If the sensor resistance is not within range after
90 seconds, the control will raise the alarm.
If the unit is in non−communicating mode and it goes to second stage due to
ambient temperature being below second stage lock−in setting (E48).
Factory Test Mode.
Solution
1
Compressor protector is open.
S
Check for high head pressure
S
Check compressor supply voltage
2
Outdoor unit power disconnect is open.
3
Compressor circuit breaker or fuse(s) is
open.
4
Broken wire or connector is not making
contact.
5
Low or high pressure switch open if present
in the system.
6
Compressor contactor has failed to close.
Page 38
Solution Solution Solution
Clearing Status
Clears the error
after current is
sensed in the run
and start winding
for two seconds,
service removed or
power reset.