Lennox iComfort S30 Installation And Setup Manual page 61

Table 1 Alert Codes and Troubleshooting
Applicable
Alert Priority
System
Code Condition
Component(s)
Moderate
417 Outdoor unit
/ Critical
Equipment
interface module
418 Moderate
and outdoor unit
Equipment
419 Critical interface module
and outdoor unit
Air handler or
equipment
420 Critical
interface module
Equipment
421 Critical interface module
and outdoor unit
Critical alerts are displayed on the Home screen, in the Homeowner alert button, and in the Installer alert button.
Minor and moderate alerts are found only in the Installer alert button.
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 peri­
od, 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:
√ The applicable system component detects either a open, shorted or tem­
Discharge Sensor Faulty
perature out of range 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 pro­
cedure. 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.
√ The W output (code E418) on the outdoor unit has reported more than five
W Output hardware Fault
Lockout
strikes.
√ 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-communicat­
ing heat pump.
The W output terminal on the outdoor unit is not wired correctly.
W External Miswire Fault
√ Voltage sensed on W output terminal when Y1 out is deactivated.
61
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 assembly
(whichever is applicable). Power
up system component after re­
placing the applicable part which
will clear the alert code / priority
condition.
Automatically clears after fault sig­
nal is removed.
Automatically clears after power
recycled.
Automatically clears when W1 sig­
nal is removed.
Automatically clears once voltage
is not sensed on output or power
is cycled.