Lennox S40 - Page 56

56
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
200
Service
Urgent
GF Rollout Limit Switch
Open
The furnace roll out limit switch is open. Correct the cause of roll out trip.
• Reset roll out switch.
• Test the furnace operation.
• Check for blocked or obstructed vent pipe (Intake and/or Exhaust).
• Check for ame stability, if ame is unstable, look for cause.
Automatically clears
after the furnace roll
out switch is closed.
201
Service Soon
/Service
Urgent
IU Blower Motor Fault
Lost communication with indoor blower motor.
• Possible causes include power outage, brown-out, motor not powered, loose wiring, condensation on
system component control without cover on breaker.
• Problem may be on system component control or motor side.
Automatically clears
after communication is
restored.
202
Service
Urgent
IU Blower Motor & Unit
Size Mismatch
The unit size code for the indoor unit and the size of blower motor do not match. Incorrect appliance unit size
code selected.
• Remove the thermostat from the system while applying power and reprogramming.
• Check for proper conguring under unit size codes for furnace/air handler in conguration guide or in
installation instructions.
Automatically clears
after the correct match
is detected following a
reset.
203
Service
Urgent
IU Invalid Size Unit
Code
The unit size code for the indoor unit has not been selected or set incorrectly.
• Verify that the correct unit size code is congured. Unit size codes for furnace and air handler are listed in
the system component conguration guide or installation instruction.
• Remove the thermostat from the system while applying power and set the unit size code per instructions
provided in the indoor unit installation instruction.
Automatically clears
after the correct match
is detected following a
reset.
204
Service
Urgent
GF Check Gas Valve
There is an issue with the furnace gas valve.
• Check gas valve operation and wiring.
• Check for voltage to the gas valve.
Automatically clears
after the issue is
corrected.
205
Service
Urgent
GF Gas Valve Relay
Contact Closed
The furnace gas valve relay contact is closed.
• Check wiring on control and gas valve. The relay is located on the furnace control .
• If issue continues replace furnace control.
Automatically clears
after the issue is
corrected.
206 Service Soon
GF Gas Valve 2nd
Stage Relay Fault
The furnace gas valve second-stage relay is faulty.
• Furnace will operate on rst-stage for the remainder of the heating demand.
• If unable to operate second-stage, replace furnace control.
Automatically clears
after the issue is
corrected.
207
Service
Urgent
GF HSI Sensed Open
The furnace hot surface igniter is open.
• Measure the resistance of hot surface igniter.
• Replace the igniter if it is not within the specied range found in furnace installation instruction.
Automatically clears
after the issue is
corrected.