Lennox iComfort S30 Installation And Setup Manual page 57

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)
223 Critical Furnace
224 Critical Furnace
225 Moderate Furnace
226 Critical Furnace
227 Moderate Furnace
228 Moderate Furnace
229 Minor Furnace
240 Moderate Furnace
Table 18. Alert Codes and Troubleshooting
Actual
Displayed Alert Component or System Operational State and Troubleshooting Tip
Text
The furnace low pressure switch is open.
• Check pressure (inches w. c.) of the low pressure switch closing during a heat call.
Low Pressure
• Measure operating pressure (inches w. c.).
Switch Open
• Inspect vent and combustion air inducer for correct operation and restriction.
• Check for blocked cold end heater box or condensate drain and cracked hoses.
The furnace low pressure switch is stuck closed.
• Check operation of low pressure switch to see if it is stuck closed for longer than 150 seconds
Low Pressure
during a heat call.
Switch Stuck
Closed
• Measure operating pressure (inches w. c.).
• Inspect vent and combustion air inducer for correct operation and restriction.
The furnace high pressure switch will not close.
• Check pressure (inches w. c.) of high pressure switch closing during a heat call.
High Press.
Switch Failed to • Measure operating pressure (inches w. c.).
Close
• Inspect vent and combustion air inducer for correct operation and restriction.
• Check for blocked cold end heater box or condensate drain and cracked hoses.
The furnace high pressure switch will not open.
High Pressure
• Check operation of high pressure switch closing during a heat call.
Switch Stuck
• Measure operating pressure (inches w. c.).
Closed
• Inspect vent and combustion air inducer for correct operation and restriction.
The furnace low pressure switch is open while in run mode.
• Check pressure (inches w. c.) of low pressure switch closing during a heat call.
Lo Pressure
Switch Open in • Measure operating pressure (inches w.c.).
Run Mode
• Inspect vent and combustion air inducer for correct operation and restriction.
• Check for blocked cold end heater box or condensate drain and cracked hoses.
The furnace control is not able to calibrate the pressure switch. Unable to perform pressure
switch calibration.
Inducer / Press.
• Check vent system and pressure switch wiring connections.
Switch Calib.
Failure
• Check the drain trap for blockage.
• Check for blocked cold end heater box or condensate drain and cracked hoses.
Ignition on High Furnace control switched to high fire ignition because low fire pressure switch did not close in
Fire allowed time.
The furnace flame current is low.
• Check micro-amperes of the flame sensor using thermostat diagnostics.
Low Flame
• Clean or replace the flame sensor.
Current - Run
• Measure voltage of neutral to ground to ensure good unit ground.
Mode
• Clean face of burner assembly.
• Check for AC voltage from flame sensor electrode to ground.
57
How to clear alert code
Automatically clears after the
issue is corrected.
Automatically clears after the
issue is corrected.
Automatically clears after the
issue is corrected.
Automatically clears after the
issue is corrected.
Automatically clears after the
issue is corrected.
Automatically clears after a
successful calibration.
No action is required.
Automatically clears after a
proper micro-amp reading has
been sensed.