Lennox EIM - Page 22

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Table 1. Alert Codes and Troubleshooting
GF= Gas Furnace, AH=Air Handler, ID=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OD=Outdoor Unit (AC or HP), PA=Pure Air S, ZA=Zone system and
TS=Thermostat
Alert
Code
Priority
Condition
Actual Displayed
Alert Text
Under dealer
control center >
Notications
Component or System Operational State and Troubleshooting Tip
How to clear
alert code
418 Service Soon
OD EIM
W Output
Hardware Fault
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.
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.
Automatically clears after
fault signal is removed.
419
Service
Urgent
OD EIM
W Output
Hardware Fault
Lockout
The W output has reported more than ve errors.
The system will shut down the outdoor unit.
The W output (alert code 418) on the outdoor unit has reported more than ve strikes.
Disconnect thermostat wire from W and verify there is no 24VAC on the W.
If 24VAC is present, replace the outdoor control.
Automatically clears after
power recycled.
420 Service Soon
AH EIM Defrost
Out Of Cycle
The heat pump defrost cycle has taken more than 20 minutes to complete.
Defrost cycle lasts longer than 20 minutes.
Check heat pump operation.
This is applicable only in communicating indoor unit with non-communicating heat pump.
Automatically clears when
W1 signal is removed.
421
Service
Urgent
OD EIM W
External Miswire
Fault
The W output terminal on the outdoor unit is not wired correctly. Voltage sensed on W output terminal when Y1
out is deactivated.
Automatically clears once
voltage is not sensed on
output or power is cycled.
-- Service Soon --
Possible loose or mis-wired connections or two zone sensors are assigned the same zone number. Two dashes
will be displayed on the S30 thermo󰀬at for indoor temperature and/or zone sensor. The sy󰀬em will go into
central mode. Individual zone functions is disabled. Anytime the zone sensor loses communication with the
damper control module, the entire sy󰀬em will go into central mode. If two sensors are assigned the same zone
number, this could result in the double dashes to appear as well.
If two zone sensors are
assigned the same zone
number, this could cause
the double dashes to
appear. If loose or mis-
wired connection was
conrmed, correct the issue
and run the re-conguration
procedure.