Sears N9MP1, N9MP2, 9MPD Gas Valve Diagnostic Codes See Figure, Circulating Fan G Request, Off

10. Sequence of Operation & Diagnostics

The following is the normal operating sequence for the control system.

Cooling (¥) Request:

24 VAC signals applied to Y & G terminals of EFT (electronic fan timer) control.

•Cool motor speed energized after 6 second Cool Fan On Delay time.

Y & G signals removed from EFT.

•Cool motor speed de-energized after 60 second Cool Fan Off Delay time.

Circulating Fan (G) Request:

24 VAC signals applied to G terminals of EFT control.

•Heat motor speed energized without delay.

G signal removed from EFT.

•Heat motor speed de-energized without delay.

Heating (W) Request:

24 VAC signals applied to W terminal of EFT control.

•Inducer motor turns on.

•The gas valve solenoid energizes.

•Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.

•After the pilot lights, the main burners energize and light.

•Timed from the opening of the main gas valve, the control will delay 30 seconds before switching the fan to Heat speed.

W signal removed from EFT.

•The gas valve de-energizes and the main burners go out.

•The inducer runs at its present speed for a 30 second postpurge period.

•Timed from the gas valve de-energizing, the Heat fan speed de-energizes after the selected Heat Fan Delay time expires.

Heating Request with Gas Supply Line Shut Off:

24 VAC signals applied to W terminal of EFT control.

•Inducer motor turns on.

•The gas valve solenoid energizes.

•Following a 3 second prepurge delay, the pilot valve opens and the ignitor begins to warm up.

•The ignitor glows red-hot for 30 seconds, then turns off.

•The igniter stays off for 25 seconds, then begins to warm-up again.

•The igniter glows red-hot for 30 seconds, then turns off.

•The pilot valve closes 3 seconds after the igniter de-energizes.

•The inducer de-energizes 5 seconds after the pilot valve closes.

•The SmartValve proceeds to soft lockout and flashes error code 6.

•The control exits soft lockout after 5 minutes and begins another ignition sequence.

Gas Valve Diagnostic Codes (See Figure 43)

OFF

=

Control

not

powered

Heartbeat

=

Normal

Operation

(Standby

or

call for

heat)

1

Flash

=

Not

used

2

Flashes

=

Pressure

switch

closed

when

should

be

open

3

Flashes

=

Pressure

switch

circuit

was

still

sensed

as open

30

seconds

after

the inducer

was

energized.

System is

in 5

minute delay

mode,

with

inducer

off. After

5-minute delay, a new ignition sequence will be initiated.

(Note:

SV9541M

On/Off

switch

in

off

position

during a call for

heat

will generate

this diagnostic

code)

4

Flashes

=

Limit

switch

string

open

5

Flashes

=

Flame

sensed out

of sequence

-

Flame

signal

still

present.

6

Flashes

+

1

Note

1

=

Soft

Lockout

-Maximum

retry

count

exceeded

(failed to

light

within

4 trials

for

ignition)

6

Flashes

+

2

Notes

1,2

=

Soft

Lockout

-Maximum

recycle

count

exceeded

-

Last

failure was Flame Sense Lost During Run

6

Flashes

+

3

Notes

1,2

=

Soft

Lockout

-Maximum

recycle

count

exceeded

-

Last

failure

was

Airflow

Proving

Circuit

Opened

During

Run

6

Flashes

+

4

Notes

1,2

=

Soft

Lockout

-Maximum

recycle

count

exceeded

-

Last

failure

was

Limit

Circuit Opened

During

Run

7

Flashes

=

Soft

Lockout

Due

to Limit

Trips

Taking

Longer

than

2 minutes

to

Reset;

Auto Reset

After

1

Hour

if

Call

for

Heat

Still

Present.

Reset

by

Cycling

Call

for

Heat

at

Any

Time.

NOTE 1 : The

6 + X designation

indicates

a combination

of flash

codes:

6 flashes

shows

the

control

is in soft

lockout,

followed

by X flashes

[_ 44001 111400