Lennox XP17-024-230-01 Installation And Service Procedure page 16

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.
Heat Pump Control
iComfortt iComfortt iComfortt
LEDs
-enabled -enabled -enabled
Thermostat Thermostat Thermostat
DS11 DS11
DS14 Red DS14 Red
Display Display Display
Green Green
Moderate
Slow flash On Alert Code
Critical Alert
Fast flash On
Code 415
Moderate /
Off Fast flash Critical Alert
Code 417
3 fast
Moderate /
flashes
Critical Alert
Off
then
Code 418
pause
3 fast
Moderate /
flashes
Critical Alert
On
then
Code 419
pause
3 fast
Critical Alert
flashes
Off
then Code 421
pause
Simultaneous fast
flashes 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 6. Compressor Fault and Lockout LED Codes and Related iComfortt-Enabled Thermostat Alert Codes
NOTE — See notes 1 and 2 in table below for duration of fast / slow flashes and pause.
Heat Pump Control
iComfortt
LEDs
-enabled
Thermostat
DS15 DS13
Display
Yellow Red
Moderate/
Critical
Off On
Code 400
XP17
Condition Condition Condition
Discharge line
temperature fault
414
Discharge line
temperature
lockout
Discharge sensor
fault
W output
hardware fault
W output
hardware fault
lockout
W external
miswire fault
Second-stage
None
heat lock-in
OEM mode
Possible
Condition
Cause(s)
Thermostat
Compressor
demand signal
3
Alert internal Y1 is present, but
overload trip compressor not
running
Possible Cause(s) Possible Cause(s) Possible Cause(s)
This code indicates 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 heat pump control (A175) 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.
When auxiliary heat output is detected as active. Fault in the heat pump control.
Replace heat pump control.
If heat pump control recognizes five output hardware fault events during a single
cooling demand, the heat pump control will initiate a lockout.
When auxiliary heat output is detected as active after compressor has been
de-energized.
If the unit is in non-communicating mode and it goes to second stage due to ambi­
ent 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 16
Solution Solution Solution
Clearing Sta­
tus
Clears the error
after current is
sensed in the
run and start
winding for two
seconds, ser­
vice removed or
power reset.