Lennox iComfort S30 Installation And Setup Manual page 65

Initial notification of critical alerts will pop up on the home screen and will be listed under notification menu. Minor and moderate alerts are found only under the notification menu.
* Current Lennox modulating outdoor units are XC20, XP20, XC25 and XP25.
Applicable
Alert Priority
System
Code Condition
Component(s)
Moderate
417 Outdoor unit
/ Critical
Equipment
interface
418 Moderate
module and
outdoor unit
Equipment
interface
419 Critical
module and
outdoor unit
Air handler
or equipment
420 Critical
interface
module
Equipment
interface
421 Critical
module and
outdoor unit
Table 18. Alert Codes and Troubleshooting
Actual
Displayed Alert Component or System Operational State and Troubleshooting Tip
Text
SYSTEM DETECTION AND Operation:
The outdoor unit discharge line temperature sensor is either open, short-circuited or the
temperature is out of sensor range.
• This fault is detected by allowing the unit to run for 90 seconds before checking discharge line
sensor resistance.
• If the discharge sensor resistance is not within range after 90 second period, the control will
display the priority condition as moderate.
• If the moderate condition continues for 10 minutes, the system changes the priority condition
to critical.
POSSIBLE CAUSES:
Discharge
• The applicable system component detects either an open, shorted or temperature out of range
Sensor Faulty
condition.
• Discharge sensor leads located in wrong pin positions in harness plug-in connector. Refer to
the applicable unit installation and service procedure and locate the terminal descriptions table
to verify cable harness assembly wiring pin positions are correct.
POSSIBLE SOLUTIONS:
• Check the resistance of the discharge sensor and compare to temperature resistance chart
located in the applicable unit installation and service procedure. If sensor resistance is out of
range then replace the discharge line temperature sensor.
• If discharge sensor wring leads are located in the wrong connector pin-out then order a
replacement cable assembly.
There is a faulty W output circuit.
• W terminal is energized while in cooling mode.
• Possible cause may be a stuck closed relay on the control, or something external to the control
that is energizing W terminal when it should not be energized.
W Output
Hardware Fault
• Disconnect any wiring from the W terminal.
• If 24VAC is still present on the terminal, then it is a stuck relay.
• If 24VAC disappears, then there is a need to check any of the wires hooked up to the W
terminal.
The W output has reported more than five errors.
• The system will shut down the outdoor unit.
W Output
hardware Fault • The W output (code E418) on the outdoor unit has reported more than five strikes.
Lockout
• Disconnect thermostat wire from W and verify there is no 24VAC on the W.
• If 24VAC is present, replace the outdoor control.
The heat pump defrost cycle has taken more than 20 minutes to complete.
• Defrost cycle lasts longer than 20 minutes.
Defrost Out of
Control
• Check heat pump operation.
• This is applicable only in communicating indoor unit with non-communicating heat pump.
The W output terminal on the outdoor unit is not wired correctly. Voltage sensed on W output
W External Mis-
terminal when Y1 out is deactivated.
wire Fault
65
How to clear alert code
Moderate - Automatically clears
after fault signal condition is no
longer present.
Critical - Power down the
system component and either
replace faulty sensor or cable as-
sembly (whichever is applicable).
Power up system component af-
ter replacing the applicable part
which will clear the alert code /
priority condition.
Automatically clears after fault
signal is removed.
Automatically clears after power
recycled.
Automatically clears when W1
signal is removed.
Automatically clears once volt-
age is not sensed on output or
power is cycled.