Lennox S40 - Page 68

68
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
413
Service
Urgent
OU High Pressure
Switch Strikes Lockout
The high pressure switch has opened ve times during one cooling demand.
• Thermostat will shut down the outdoor unit.
• Open high pressure switch error count reached ve strikes.
• Check system charge using superheat and sub-cooling temperatures.
• Check outdoor fan operation.
• Check for dirt or debris blocking air ow to outdoor unit.
• Reset by putting outdoor unit control in test mode or resetting low voltage power.
Automatically clears
when the system
detects that the issue
no longer exists.
414 Service Soon
OU High Discharge
Line Temperature
The discharge line temperature is higher than the recommended upper limit of 279ºF.
• Discharge line temperature is greater than 279ºF.
• Make sure coil is clean and airow unobstructed in and out of condenser.
• Check system operating pressures and compare to unit charging charts in installation manual.
Automatically clears
after discharge
temperature is less
than 225ºF.
415
Service
Urgent
OU High Discharge
Line Temp Strikes
Lockout
The discharge line temperature has been consistently higher than the recommended upper limit of 279ºF.
• Discharge line high temperature error count reached ve strikes during a single demand.
• Make sure coil is clean and airow unobstructed in and out of condenser.
• Check system charge using superheat and sub cooling temperatures.
• Reset by putting outdoor control in test mode or resetting low voltage power.
Correct issue and cycle
power to the system.
416 Service Soon OU Coil Sensor Faulty
The outdoor coil sensor is either open, short-circuited or the temperature is out of sensor range.
• Outdoor unit control will not perform demand or time / temperature defrost operation. (System will still heat
or cool.)
• This fault is detected by allowing the unit to run for 90 seconds before checking sensor resistance. If the
sensor resistance is not within range after 90 seconds, the control will display a service soon condition.
• Plug-in sensor harness correctly.
• Check resistance of sensor to determine if it is open, shorted, out of temperature calibration or out of
ambient temperature range. Replace if out-of-specications.
Automatically clears
when outdoor unit
control detects proper
sensor readings.
Reset power to clear
alert code.