Lennox S40 - Page 77

77
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
435 60
Service
Soon/Service
Urgent
OU Inverter EEPROM
Checksum fault
Inverter internal error.
• When this error occurs, the outdoor control will cycle power to the inverter by opening the contactor for two
minutes – service soon condition.
• Outdoor control will cycle power to the inverter three times and then outdoor unit is locked out – service
urgent condition.
• Inverter LEDs will ash code 60.
• Refer to the unit service documentation for detailed troubleshooting procedures.
Inverter ash code 60.
The sequence is:
• Red LED: Six Flashes
• Green LED: Off
NOTE: Inverter normal operations with no error code present is as follows. Red LED is ON and Green LED
is OFF.
To clear alert code
disconnect power
to outdoor unit and
restart.
436 62
Service
Soon/Service
Urgent
OU Inverter High Heat-
Sink Temperature
Inverter heat sink temperature exceeded limit.
• This occurs when the heat sink temperature exceeds the inverter limit. Inverter will issue inverter alert code
13 rst and slow down to try to cool the heat sink.
• If temperature remains high, outdoor unit will stop both compressor and fan – service soon condition.
• Anti- short cycle is initiated.
• If condition occurs ve times within an hour, system will lockout – service urgent condition.
• The screws that hold the inverter to the inverter board were loose causing poor contact between these two
components.
• Tighten screws that hold the heat sink to the inverter control board.
NOTE: Wait ve minutes for all capacitors to discharge before checking screws.
• Inverter LEDs will ash code 62.
• Refer to the unit service documentation for detailed troubleshooting procedures.
Inverter ash code 62.
The sequence is:
• Red LED: Six Flashes
• Green LED: Two Flashes
NOTE: Inverter normal operations with no error code present is as follows. Red LED is ON and Green LED
is OFF.
Service soon condition
will automatically clear
when the inverter
sends an alert code
clear message.
Service urgent
condition is cleared by
disconnecting power
to the outdoor unit and
restart.