Lennox International Inc XP2101, XC2105, XC1702, XP1906, XP1702 Alert Codes and Troubleshooting

Table 5. Alert Codes and Troubleshooting			Critical alerts are displayed on Home (user) screen, in the Homeowner alert button, and in the Installer
			alert button. Minor and Moderate alerts are found only in the Installer alert button.
Alert
Code	Priority	Alert Text	Steps to clear
180	Critical	(Furnace / Air Handler / Outdoor Unit) The ther-	In normal operation after control recognizes sensors, the alarm will be sent if valid temperature
		mostat has found a problem with the (furnace,	reading is lost. Compare outdoor sensor resistance to temperature/resistance charts in unit installa-
		air−handler or outdoor unit) outdoor sensor.	tion instructions. Replace sensor pack if necessary. At the beginning of (any) configuration, furnace
			or air−handler control will detect the presence of the sensor(s). If detected (reading in range), ap-
			propriate feature will be set as ’installed’ and shown in the ’About’ screen. The alarm/fault will clear
			upon configuration, or sensing normal values.
200	Critical	(Furnace) The furnace rollout limit switch is	Correct the cause of rollout trip. Reset rollout switch. Reset power to clear. Test the furnace opera-
		open.	tion. The alarm/fault clears after the furnace rollout switch is closed.
201	Critical	(Furnace / Air Handler) The system has lost	Lost communication with indoor blower motor. Possible causes include: power outage, brown−out,
		communication with the (furnace or air−handler)	motor not powered, loose wiring, condensation on air handler control without cover on breaker.
		indoor blower motor.	Problem may be on control or motor side. Cleared after communication is restored.
202	Critical	(Furnace / Air Handler) The unit size code for	Incorrect appliance unit size code selected. Check for proper configuring under Unit Size Codes for
		the (furnace or air−handler) and the size of blow-	Furnace/Air Handler on configuration guide or in installation instructions. The alarm/fault clears after
		er motor do not match.	the correct match is detected following a reset. Remove the thermostat from the system while apply-
			ing power and reprogramming.
203	Critical	(Furnace / Air Handler) The unit size code for	No appliance unit size code selected. Check for proper configuring under: Unit Size Codes for Fur-
		the (furnace or air−handler) has not been se-	nace/Air Handler on configuration guide or in installation instructions. Critical Alert. The alarm/fault
		lected.	clears after the correct match is detected following a reset. Remove the thermostat from the system
			while applying power and reprogramming.
204	Critical	(Furnace) There is a problem with the furnace	Check gas valve operation and wiring. The alarm/fault clears after the issue is corrected.
		gas valve.
205	Critical	(Furnace) The furnace gas valve relay contact	Check wiring on control and gas valve. The alarm/fault clears after the issue is corrected.
		is closed.
206	Critical	(Furnace) The furnace gas valve 2nd stage	Furnace will operate on 1st stage for the remainder of the heating demand. The alarm/fault will clear
		relay is faulty.	after the issue is corrected. If unable to operate 2nd stage, replace control.
207	Critical	(Furnace) The furnace hot surface igniter is	Measure the resistance of hot surface igniter. Replace the it if it is not within the specified range
		open.	found in IOM. The alarm/fault clears after the issue is corrected.
223	Critical	(Furnace) The furnace low pressure switch is	Check pressure (inches w.c.) of low pressure switch closing during a heat call. Measure operating
		open.	pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction.
			The alarm/fault clears after the issue is corrected.
224	Critical	(Furnace) The furnace low pressure switch is	Check operation of low pressure switch to see if it is stuck closed for longer than 150 seconds during
		stuck closed.	a heat call . Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for
			correct operation and restriction. The alarm/fault clears after the issue is corrected.
225	Critical	(Furnace) The furnace high pressure switch is	Check pressure (inches w.c.) of high pressure switch closing during a heat call. Measure operating
		failing to close.	pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction.
			The alarm/fault clears after the issue is corrected.
			table continued on next page

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