Lennox iComfort S30 Installation And Setup Manual page 59

Initial notification of critical alerts will pop up on the home screen and will be listed under notification menu. Minor and moderate alerts are found only under the notification menu.
* Current Lennox modulating outdoor units are XC20, XP20, XC25 and XP25.
Applicable
Alert Priority
System
Code Condition
Component(s)
273 Critical Furnace
274 Critical Furnace
275 Critical Furnace
276 Critical Furnace
290 Critical Furnace
291 Critical Furnace
Furnace or air
292 Critical
handler
294 Critical Furnace
295 Minor Furnace
Table 18. Alert Codes and Troubleshooting
Actual
Displayed Alert Component or System Operational State and Troubleshooting Tip
Text
The furnace flame is going off during a heating cycle. The system will go into WatchGuard
mode.
WatchGuard
• Check micro-amperes of flame sensor using thermostat diagnostics.
- Flame fail in
• Clean or replace sensor.
Run Mode
• Measure voltage of neutral to ground to ensure good unit ground.
• Clean face of burner assembly.
The furnace limit switch has been open for more than three minutes. The system will go into
WatchGuard -
WatchGuard mode.
Primary Limit
• Check firing rate and air flow.
Switch Open
• Check for air blockage.
The furnace flame is out of sequence. The system will go into WatchGuard mode.
WatchGuard -
Flame Out of • Shut off gas.
Seq. No Flame
• Check for gas valve leak.
The furnace is not able to calibrate or the high pressure switch opened or failed to close in run
WatchGuard
mode. The system will go into WatchGuard mode.
- Calibration
• Check vent system
Failure
• Check pressure switch wiring connections.
There is a problem with the furnace ignition circuit. The system will go into WatchGuard mode.
• Measure resistance of hot surface igniter.
Ignition Circuit
Problem
• Replace the hot surface igniter; it is not within specifications.
• Measure voltage to igniter.
The heating airflow is below the minimum required level. The system will go into WatchGuard
Heat Airflow
mode.
Restricted
• Check for dirty air filter(s) and other air flow restrictions.
Below Min
• Check blower performance.
The indoor unit blower motor will not start. The system will go into WatchGuard mode.
• Indoor blower motor unable to start.
Indoor Blower
Motor Start
• This could be due to seized bearing, stuck wheel, and obstructions.
Problem
• Replace motor, motor module or wheel if assembly does not operate or meet performance
standards.
There is over current in the furnace inducer motor. The system will go into WatchGuard mode.
Inducer Motor
• Check combustion blower bearings, wiring and amps.
Overcurrent
• Replace furnace inducer motor if it does not operate or does not meet performance standards.
The indoor blower motor is overheating. Indoor blower motor over temperature (motor tripped on
internal protector).
Indoor
• Check motor bearings and amps.
Blower Over
Temperature
• Replace indoor blower motor if necessary.
• Check for high duct static.
59
How to clear alert code
Automatically clears when a heat
call ends successfully.
Automatically clears when a heat
call ends successfully.
Automatically clears on success-
ful ignition.
Automatically clears when the
furnace calibrates itself success-
fully.
Automatically clears on success-
ful ignition
Automatically clears when a heat
call ends successfully.
Automatically clears after the
indoor blower motor starts suc-
cessfully.
Automatically clears after inducer
motor current is sensed to be in-
range after the ignition following
either WatchGuard mode or unit
reset.
Automatically clears after blower
demand is satisfied.