Lennox International Inc G50UH-36A-070 LED#1ON, YEs, sPOLARITYREVERSED?, YESi, Proper Ground?

SURELIGHT® CONTROL

HEATING SEQUENCE OF OPERATION

NORMAL HEATING MODE

ABNORMAL HEATING MODE

I

POWER ON

]

I

GAS VALVE OFF. COMBUSTION

AIR INDUCER

ON.

_'

I

INDOOR BLOWER ON.

CONTROL SELF-CHECK OKAY'_

I,_

_

LED #1 ALTERNATING

FAST FLASH

I

"

; NO

LED#2 ALTERNATING

FAST FLASH

I

CHECK FOR BROKEN IGNITOR OR

-I

GAS VALVE OFF. COMBUSTION

AIR INDUCER

OFF.

v

aYES _

I

INDOOR BLOWER DELAY OFF.

,sPOLARITYREVERSED?

_1

LED#1ON

I

i- I

I

I

LED #2 ON

I

I NO

/I

I

(R__

TURNING

MAIN POWER

OFF)

LED#1

AND LED#2

/

ALTERNATING

FAST

J_

1'

_

POLARITY REVERSED.

FLASH,

SIGNAL

NO

•

I YESI

I

LED #1 -- FAST FLASH

HOLDS UNTIL UNIT IS ._--I

ISTHERE

ISVOLTAGE

I NO I

LED #2 -- SLOW FLASH

PROPERLY GROUNDi_I

PROPER GROUND?

_

ABOVE

75 VOLTS?

I_-----'

I

--

'

YES/

II _I LED#1ANDLED#2ALTERNATINGFAST

_I

•

NO

I'--ml FLASH. SIGNAL HOLDS UNTIL VOLTAGE I

ROLLOUT SWITCH CLOSED?

_

I_ I

RISES ABOVE

75 VOLTS.

I

YESi

in,--

I1"I"1

GAS VALVE OFF. COMBUSTION

AIR INDUCER

OFF.

'_

_1

INDOOR BLOWER OFF WITH DELAY.

GAS VALVE

I

I

LED #1 -- ON. LED #2 -- SLOW FLASH,

I

DE-ENERGIZED?

I

ISEQUENCE

HOLDS UNTIL ROLLOUT SWITCH CLOSES.

YEs_

	LED #1 -- SLOW FLASH
	NORMAL	OPERATION:		I
	LED #2 -- SLOW FLASH
I	THERMOSTAT	CALLS	FOR HEAT:	I
	LED #1 -- FAST FLASH			I
	LED #2 -- FAST FLASH
i	YES
	IS COMBUSTION		AIR	I
	PRESSURE	SWITCH	OPEN?	14

YES _1

I IS(HUMCOMBUSTIONTERMINAL AIRIS ENERGIZEDINDUCER ENERGIZED?WITHC.A. .) 4

NO

COMBUSTION AIR INDUCER OFF.

INDOOR BLOWER OFF WITH DELAY.

LED #1 OFF

LED #2 SLOW FLASH

GAS VALVE OFF.

(Sequence holds until pressure switch closes or thermostat resets control,)

HASSWITCHCOMBUSTIONCLOSED INAIR2.5 PRESSUREMINUTES?		1_
YES		I
15-SECOND COMBUSTION	AIR INDUCER PREPURGE
N T ATED BY CLOSED	PRESSURE SW TCH.	I
		m
YES
CONTINUED	NEXT PAGE

PRESSURE SWITCH IS IN WATCHGUARD MODE. GAS VALVE OFF. COMBUSTION AIR INDUCER OFF. INDOOR BLOWER OFF WITH DELAY,

LED #1 -- OFF. LED #2 -- SLOW FLASH,

IS 5-MINUTE RESET PERIOD COMPLETE?

Page 31