Lennox S40 - Page 66

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Table 21. Lennox S40 Smart Thermostat Alert Codes and Troubleshooting
E2A=Errors to Action, GF= Gas Furnace, AH=Air Handler, IU=Indoor unit (GF or AH), HP=Heat Pump, AC=Air Conditioner, OU=Outdoor Unit (AC or HP), PA=Pure Air S, ZA=Zone system,
SRS=Smart Room Sensor, TS=Thermostat , IAQ- IAQ Monitor and WE=Wi-Fi Extender
Alert
Code
Inverter
Flash
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
382
Service
Urgent
EIM Relay W1 Fault
Relay W1 failure (furnace or air handler modes only). W1 relay is energized but input is not sensed after
three seconds.
Automatically clears
when W1 relay input is
sensed.
400 Service Soon
OU LSOM Comp.
Internal Overload
Tripped
The compressor internal overload has tripped.
• Thermostat demand Y1 is present; however compressor is not running.
• Check power to unit.
This alert code is
automatically cleared
after current is sensed
in both RUN and
START sensors for
at least two seconds
or after service is
removed, or after
power reset.
401
Information
Only-Dealer
OU Compressor Long
Run Cycle
Either the compressor ran for more than 18 hours continuously while attempting to cool the home during a
single demand or the system refrigerant pressure is low.
• Alert code will not lockout system.
• If the two-stage outdoor unit has an outdoor control with ashing LED lights then the unit will run in low
speed;
• An outdoor control with a seven-segment display, the outdoor control will display alert code 401, but
continue to run in high speed.
• If the outdoor unit is a heat pump, and the outdoor temperature is less than 65°F, alert code 401 is ignored.
• Also monitors low pressure switch trips.
Automatically clears
after 30 consecutive
normal run cycles or
power reset.
402 Service Soon
OU System Pressure
Trip
• Either the discharge or suction pressure level is out-of-limits, or the compressor has overloaded.
• Check discharge or suction pressure.
Automatically clears
after four consecutive
normal compressor run
cycles.
403 Service Soon
OU Compressor Short-
Cycling
The compressor ran for less than three minutes to satisfy a thermostat demand.
Automatically clears
after four consecutive
normal compressor run
cycles.
404
Service
Urgent
OU Compressor Rotor
Locked
The compressor rotor is locked up due to either:
• Run capacitor short.
• Bearings are seized.
• Excessive liquid refrigerant.
NOTE: May need to install hard start kit.
Automatically clears
after four consecutive
normal run cycles or
after power reset.
405
Service
Urgent
OU Compressor Open
Circuit
The compressor circuit is open due to:
• Power disconnection -
• Open fuse
Automatically clears
after one normal
compressor run cycle.