Lennox International Inc 070V36B, 090V36C, 110V60C, 090V60C Page, Call For Heat Satisfied

Troubleshooting: Heating Sequence of Operation (Continued)

C A L L

F O R

H E A T

IGNITION AND CALL FOR HEAT WITH SINGLE−STAGE THERMOSTAT

4

Safety

Check

Verify There

Is No Main Burner

Flame

Indoor Blower OFF After

Heat OFF Delay

YES

(Low Heat Speed)

Limit

Indoor Blower

Limit

Switch

NO

De−Energize

Combustion Air

Error Code

ON

Closes Within 3

NO

Gas Valve

Inducer ON

Flashes

(100% Speed)

Closed?

Minutes?

(100%)

Indoor Blower OFF

After Heat OFF Delay

YES

(High Heat Speed)

Combustion Air

Inducer ON

Rollout

(100%)

Rollout

Soft Lockout:

Circuit

NO

De−Energize

Error Code

Circuit

Error Code

1

Closed?

Gas Valve

Flashes

Closes?

Flashes

Indoor Blow-

L

YES

er ON

I

(70%)

G

YES

NO

H

Combustion Air Inducer

OFF After Post−Purge

T

O

Low

High

F

Pressure

NO

Error Code Flashes

Pressure

NO

Error Code Flashes

Indoor Blower OFF After

F

Switch

After 5 Seconds

Switch

After 5 Seconds

Heat OFF Delay

Open?

Open?

Low Pressure

High Pressure

Hard Lockout:

Switch Opens

YES

Switch Opens

Error Code

2

Flashessfl

YES

Combustion Air Inducer ON

Call

at Ignition at 70% rate speed

For

NO

YES

Heat?

NO

Low

4

YES

Pressure Switch

Pressure Switch

Calibration

Calibrations

Soft Lockout:

Call For

NO

NO

YES

Error Code

Heat

Closed Within 150

Calibration

Successful?

Attempted?

Flashes

Ends?

Seconds?

YES

Wait

NO

YES

5 minutes

Pre−Purge

15 Seconds

Indoor

Blower On?

Ignitor ON

Interpurge

20 Seconds

(15 Seconds)

Gas Valve

YES

NO

Energized

Indoor Blower OFF

NO

After Heat OFF Delay

IgnitionTrial Begins

Indoor Blower On

Ignitor ON

Delay Timer Started

1

Gas Valve

Flame

De−energized

5th

Post−Purge

Combustion Air

Soft Lockout:

Sensed Within

NO

Unsuccessful

YES

Error Code

(20 Seconds)

Inducer OFF

1

4 seconds?

Ignitor OFF

Trial?

Flashes

YES

Ignitor OFF

Wait For Ignition

1 SOFT LOCKOUT IS RESET AUTOMATICALLY AFTER ONE HOUR WITHA CALL FOR HEAT ACTIVE,

Stabilization Delay

OR BY CYCLINGTHE CALL FOR HEAT, OR BY CYCLING POWERTO THE CONTROL.

2 HARD LOCKOUT IS RESET BY CYCLING POWERTO THE CONTROL.

Set to

Low Firing Rate

Move to Mid Firing Rate

and High Firing Rate after

3B

Call For Heat Satisfied

2nd and 3rd Stage Delays

(based on DIP Switch selections)

Page 60