Lennox International Inc Zone Control Panel Troubleshooting continued, Symptom, Possible Solution

Troubleshooting (continued)

DETECTING HEATING, COOLING AND FAN PROBLEMS

Symptom	Possible Solution
	No power to control panel. Green “Normal Flashing”
Nothing comes on.	LED should be blinking, if not apply power to
	24VAC inputs of control panel. Check fuse.
	Single transformer system. Install jumper between RC
	and RH at HVAC Equipment outputs of control panel.
	Interlock switch on furnace is open – close access doors.
	Thermostat is not calling for heat. Check voltage at
Heat will not come on.	the thermostat W input on the control panel.
	Zone 2 calling while open or short at DAS inputs is
	causing control panel to respond only to Zone 1.
	Thermostat is power robbing or mechanical. Only use
	line powered electronic thermostat with a C terminal.
	Single transformer system. Install jumper between RC
	and RH at HVAC equipment outputs of control panel.
	Thermostat is not calling for cooling. Check voltage
	at the thermostat Y input on the control panel.
Cooling will not come on.	Thermostat could be invoking a timed off delay.
	Zone 2 calling while open or short at DAS inputs is
	causing control panel to respond only to Zone 1.
	Zone panel could be invoking a timed off delay.
	Thermostat is power robbing or mechanical. Only use
	line powered electronic thermostat with a C terminal.
	Check if G is energized at the zone panel.
Fan will not come on.	Check if G is energized at the thermostat.
	Check if G is energized at the air handler.
Dampers do not position on a call for heating,	System requires the Discharge Air sensor. If DAS is not
	installed, only Zone 1 calls will be recognized and dampers
cooling or fan. Heat, cooling or fan will not come on
	will not operate. Disconnect power to the control panel,
when the Zone 2 thermostat is calling.
	install the DAS and restore power to the control panel.
Fan immediately comes on with heat call.	ELECT/GAS jumper set to ELECT – change setting
	to GAS.
After a cool call, the fan stops then starts right	HVAC system has built in duct purge. Set PURGE/NO
away only to stop a short while later.	PURGE jumper on control panel to NO PURGE.
	Discharge air temperature exceeds set limit.
Fan is running but no heat, and W LED is blinking.	Allow discharge air to cool 10° below set limit and
	allow timed off delay to expire.
	Discharge air temperature dropped below set limit.
Fan is running but no cooling, and Y LED is blinking.	Allow discharge air to warm 10° above set limit and
	allow timed off delay to expire.
Both the Y and W LEDs are blinking.	An open or short in the DAS sensor has been detected.
	Install or repair the sensor.

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