Bryant 394Had Users Manual

394HAD to the manual 5f1fcab9-8ae2-4f48-bf65-1b78f880b70d

: Bryant Bryant-394Had-Users-Manual-411935 bryant-394had-users-manual-411935 bryant pdf

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Page Count: 8

NOTE: Read the entire instruction manual before starting the

installation.

These procedures are for sizes 65,000 through 150,000 Btuh units.

Index Page

SAFETY CONSIDERATIONS.....................................................1

CARE AND MAINTENANCE..................................................1-5

Air Filter Arrangement..........................................................2-3

Blower Motor and Wheel......................................................3-4

Cleaning Heat Exchanger......................................................4-5

Electrical Controls and Wiring.................................................5

Pilot ...........................................................................................5

Troubleshooting ........................................................................5

Unit Wiring Diagram ............................................................6-7

Troubleshooting Chart ..............................................................8

SAFETY CONSIDERATIONS

Installing and servicing heating equipment can be hazardous due to

gas and electrical components. Only trained and qualified person-

nel should install, repair, or service heating equipment.

Untrained personnel can perform basic maintenance functions

such as cleaning and replacing air filters. All other operations must

be performed by trained service personnel. When working on

heating equipment, observe precautions in the literature, on tags,

and on labels attached to or shipped with the unit and other safety

precautions that may apply.

Follow all safety codes. In the United States, follow all safety

codes including the National Fuel Gas Code NFPA No. 54-

1992/ANSI Z223.1-1992 (NFGC). In Canada, refer to the current

edition of the National Standard of Canada CAN/CGA-B149.1-

and .2-M91 Natural Gas and Propane Gas Installation Codes

(NSCNGPIC). Wear safety glasses and work gloves. Have fire

extinguisher available during start-up and adjustment procedures

and service calls.

Recognize safety information. This is the safety-alert symbol .

When you see this symbol on the furnace and in instructions or

manuals, be alert to the potential for personal injury.

Understand the signal word DANGER, WARNING, or CAU-

TION. These words are used with the safety-alert symbol. DAN-

GER identifies the most serious hazards which will result in severe

personal injury or death. WARNING signifies a hazard that could

result in personal injury or death. CAUTION is used to identify

unsafe practices which would result in minor personal injury or

product and property damage. NOTE is used to highlight sugges-

tions that will result in enhanced installation, reliability, or

operation.

WARNING: The ability to properly perform mainte-

nance on this equipment requires certain expertise, me-

chanical skills, tools, and equipment. If you do not

possess these, do not attempt to perform any maintenance

on this equipment other than those procedures recom-

mended in the User’s Manual. FAILURE TO FOLLOW

THIS WARNING COULD RESULT IN POSSIBLE

DAMAGE TO THIS EQUIPMENT, SERIOUS PER-

SONAL INJURY, OR DEATH.

CARE AND MAINTENANCE

For continuing high performance and to minimize possible equip-

ment failure, it is essential that periodic maintenance be performed

on this equipment. Consult your local dealer as to the proper

frequency of maintenance and the availability of a maintenance

contract.

Fig. 2—Model 394HAD Upflow

A92057

Fig. 1—Model 396HAD

Downflow

A92058

®ama

CANADIAN GAS ASSOCIATION

A P PRO VE D

R

service and

maintenance procedures

GAS-FIRED

INDUCED-COMBUSTION FURNACES

Cancels: SP04-13 SP04-19

11-1-93

394HAD

396HAD

Series C

—1—

→

WARNING: Turn off the gas and electrical supplies to

the unit before performing any maintenance or service.

Follow the operating instructions on the label attached to

the furnace. A failure to follow this warning could result

in personal injury.

WARNING: Never store anything on, near, or in contact

with the furnace, such as:

1. Spray or aerosol cans, rags, brooms, dust mops,

vacuum cleaners, or other cleaning tools.

2. Soap powders, bleaches, waxes or other cleaning

compounds, plastic or plastic containers, gasoline, kero-

sene, cigarette lighter fluid, dry cleaning fluids, or other

volatile fluids.

3. Paint thinners and other painting compounds, paper

bags or other paper products.

A failure to follow this warning could result in corrosion

of the heat exchanger, fire, personal injury, or death.

The minimum maintenance that should be performed on this

equipment is as follows:

1. Check and clean air filter each month or more frequently if

required. Replace if torn.

2. Check blower motor and wheel for cleanliness and lubrica-

tion each heating and cooling season. Clean and lubricate as

necessary.

3. Check electrical connections for tightness and controls for

proper operation each heating season. Service as necessary.

CAUTION: As with any mechanical equipment, per-

sonal injury can result from sharp metal edges, etc.,

therefore, be careful when removing parts.

A. Air Filter Arrangement

The air filter arrangement may vary depending on the application.

Refer to Table 1 or 2 for filter size information.

TABLE 1—FILTER SIZE INFORMATION FOR DOWN-

FLOW FURNACE (IN.)

FURNACE

CASING WIDTH FILTER QUANTITY

AND SIZE FILTER

TYPE

14-3/16 (2) 16 X 20 X 1 Cleanable

17-1/2 (2) 16 X 20 X 1 Cleanable

21 (2) 16 X 20 X 1 Cleanable

24-1/2 (2) 16 X 20 X 1 Cleanable

TABLE 2—FILTER SIZE INFORMATION FOR UPFLOW

FURNACE (IN.)

FURNACE

CASING WIDTH FILTER QUANTITY AND SIZE FILTER

TYPE

Side Return Bottom Return

14-3/16 (1) 16 X 25 X 1* (1) 14 X 25 X 1 Cleanable

17-1/2 (1) 16 X 25 X 1* (1) 16 X 25 X 1 Cleanable

21 (1) 16 X 25 X 1 (1) 20 X 25 X 1* Cleanable

24-1/2 (2) 16 X 25 X 1* (1) 24 X 25 X 1 Cleanable

* Factory provided with the furnace. Filters may be field modified by cutting as

required.

WARNING: Never operate unit without a filter or with

filter access door removed. A failure to follow this

warning could result in fire, personal injury, or death.

1. Downflow

Each furnace requires 2 filters which are installed in the

return-air duct. (See Fig. 3.)

To remove filters for cleaning or replacement, proceed as

follows:

a. Disconnect electrical power before removing access

door.

b. Remove blower access door after removing 2 screws.

c. Reach up behind top plate, tilt filters toward center of

return-air plenum, remove filters, and clean as needed.

Replace if torn.

d. Furnaces are equipped with permanent, washable filters.

Clean filters with tap water. Spray water through filter in

opposite direction of airflow.

e. Rinse and let dry. Oiling or coating of filters is not

recommended or required.

f. Reinstall filters.

g. Replace access door and secure with 2 screws.

h. Restore electrical power to furnace.

2. Upflow

Each furnace requires 1 or 2 filters which are installed in the

blower compartment. (See Fig. 4.)

To remove filters for cleaning or replacement, proceed as

follows:

a. Disconnect electrical power before removing access

doors.

Fig. 3—Filter Positions

A88486

RETURN-AIR

PLENUM

AIRFLOW

ACCESS DOOR

INSTALLATION

POSITION

OF FILTERS

—2—

b. Remove blower and control access doors.

c. Release filter retainer from clip at front of furnace

casing. (See Fig. 4.) For side return, clips may be used on

either or both sides of the furnace.

d. Slide filter out.

e. Furnaces are equipped with permanent, washable filters.

Clean filters with tap water. Spray water through filter in

opposite direction of airflow.

f. Rinse and let dry. Oiling or coating of filter is not

recommended or required.

g. Reinstall filter.

h. Replace access doors.

i. Restore electrical power to furnace.

B. Blower Motor and Wheel

For long life, economy, and high efficiency, clean accumulated dirt

and grease from the blower wheel and motor annually.

The following steps should be performed by a qualified service

technician:

Some motors have prelubricated sealed bearings and require no

lubrication. These motors can be identified by the absence of oil

ports on each end of the motor. For those motors with oil ports,

lubricate motor every 5 years if motor is used on intermittent

operation (thermostat FAN switch in AUTO position), or every 2

years if motor is in continuous operation (thermostat FAN switch

in ON position).

Remember to disconnect the electrical supply before removing

access doors.

Clean and lubricate as follows:

1. Remove 2 screws from blower access door (downflow

furnace only). Remove blower access door.

2. Remove vent pipe enclosure (downflow furnace only) and

disconnect short piece of vent pipe from relief box.

3. Disconnect wires from auxiliary limit on blower housing

(downflow furnace only).

4. Remove control box.

5. Remove electrical leads from numbered side of blower

speed selector. (See Fig. 4 and 5.) Note location of wires for

reassembly.

6. Remove screws holding blower assembly to blower deck

and slide blower assembly out of furnace.

7. Squeeze side tabs of blower speed selector and pull it out of

blower housing.

8. Loosen screw in strap holding motor capacitor to blower

housing and slide capacitor out from under strap.

9. Mark blower wheel, motor, and motor support in relation to

blower housing before disassembly to ensure proper reas-

sembly.

10. Loosen setscrew holding blower wheel on motor shaft.

11. Remove bolts holding motor mount to blower housing and

slide motor and mount out of housing. Disconnect ground

wire attached to blower housing before removing motor.

12. Lubricate motor (when oil ports are provided).

a. Remove dust caps or plugs from oil ports located at each

end of motor.

b. Use a good grade of SAE 20 nondetergent motor oil and

put 1 teaspoon, 5 cc, 3/16 oz, or 16 to 25 drops in each

oil port. Do not over-oil.

c. Allow time for total quantity of oil to be absorbed by

each bearing.

d. Wipe excess oil from motor housing.

e. Replace dust caps or plugs on oil ports.

13. Remove blower wheel from housing.

a. Mark cutoff location to ensure proper reassembly.

Fig. 4—Model 394HAD Upflow

A92178

DRAFT

SAFEGUARD

SWITCH

RELIEF

BOX

MOUNTING

SCREWS

FLUE

COLLECTOR

BOX

GAS

VALVE

PILOT

SPEED

SELECTOR

FILTER

RETAINER

WASHABLE

FILTER

CONTROL

BOX

Fig. 5—Model 396HAD Downflow

A92179

VENT PIPE

ENCLOSURE

CONTROL

BOX

DRAFT

SAFEGUARD

SWITCH

FLUE

COLLECTOR

BOX

AUXILIARY

LIMIT SWITCH

(NOT VISIBLE)

SPEED

SELECTOR

MOUNTING

SCREWS

RELIEF

BOX

—3—

b. Remove screws holding cutoff plate and remove cutoff

plate from housing.

c. Lift blower wheel from housing through opening.

14. Clean blower wheel and motor using a vacuum cleaner with

soft brush attachment. Do not remove or disturb balance

weights (clips) on blower wheel blades. The blower wheel

should not be dropped or bent as balance will be affected.

15. Reinstall blower wheel by reversing steps 13 a. through c.

Be sure wheel is positioned for proper rotation.

16. Reassemble motor and blower by reversing steps 5 through

11. If motor has ground wire, be sure it is connected as

before.

CAUTION: Be sure the motor is properly positioned in

the blower housing. The motor oil ports must be at a

minimum of 45° above the horizontal centerline of the

motor after the blower assembly has been reinstalled in

the furnace.

17. Reinstall blower assembly in furnace. Connect electrical

leads to blower speed selector. Please note that connections

are polarized for assembly. DO NOT FORCE.

18. Reinstall control box.

19. Reconnect wires to auxiliary limit switch on blower housing

(downflow furnaces only).

20. Reinstall vent pipe and enclosure (downflow furnaces

only).

21. Turn on electrical power and check for proper rotation and

speed changes between heating and cooling.

22. Replace blower access door and secure with 2 screws

(downflow furnace only).

C. Cleaning Heat Exchanger

The following steps should be performed by a qualified service

technician:

NOTE: Deposits of soot and carbon indicate the existence of a

problem which needs to be corrected. Take action to correct the

problem.

If it becomes necessary to clean the heat exchanger because of

carbon deposits, soot, etc., proceed as follows:

1. Turn off gas and electrical power to furnace.

2. Remove 2 screws from blower access door (downflow

furnace only). Remove control and blower access doors.

3. Remove vent pipe enclosure (downflow furnace only) and

disconnect vent pipe from relief box.

4. Remove 2 screws that secure relief box. (See Fig. 4 or 5.)

5. Disconnect wires to the following components:

a. Draft safeguard switch

b. Inducer motor

c. Pressure switch

d. Limit overtemperature switch

e. Gas valve

f. Edge connector leading to control box

6. Remove 8 screws that secure flue collector box to center

panel. Be careful not to damage sealant.

7. Remove complete inducer assembly from furnace, exposing

flue openings.

8. Clean cells using field-provided small wire brush, steel

spring cable, reversible electric drill, and vacuum cleaner.

a. Assemble wire brush and steel spring cable.

(1.) Use 48 in. of 1/4-in. diameter high-grade steel

spring cable (commonly known as drain clean-out

or Roto- Rooter cable).

(2.) Use 1/4-in. diameter wire brush (commonly known

as 25-caliber rifle cleaning brush).

NOTE: The items needed in steps (1.) and (2.) can usually be

purchased at local hardware stores.

(3.) Insert twisted wire end of brush into end of steel

spring cable, and crimp tight with crimping tool or

strike with ball-peen hammer. TIGHTNESS is very

important.

(4.) Remove metal screw fitting from wire brush to

allow insertion into cable.

b. Clean each heat exchanger cell.

(1.) Attach variable-speed, reversible drill to end of

steel spring cable (end opposite brush).

(2.) Insert brush end of cable into upper opening of cell

and slowly rotate with drill. DO NOT force cable.

Gradually insert at least 36 in. of cable into 2 upper

passes of cell. (See Fig. 6.)

(3.) Work cable in and out of cell 3 or 4 times to obtain

sufficient cleaning. DO NOT pull cable with great

force. Reverse drill and gradually work cable out.

(4.) Remove burner assembly and cell inlet plates.

(5.) Replace screws in center panel and cells before

cleaning.

(6.) Insert brush end of cable in lower opening of cell,

and proceed to clean 2 lower passes of cell in same

manner as 2 upper passes.

(7.) Repeat foregoing procedures until each cell in

furnace has been cleaned.

(8.) Remove residue from each cell using vacuum

cleaner.

(9.) Clean burner assembly using vacuum cleaner with

soft brush attachment.

(10.) Reinstall cell inlet plates and burner assembly.

Care must be exercised to center the burners in the

cell openings.

9. After cleaning flue openings, check sealant on flue collector

to ensure that it has not been damaged. If new sealant is

needed, contact your dealer or distributor.

10. Clean and replace flue collector assembly, making sure all

8 screws are secure.

11. Reinstall 2 screws in relief box.

Fig. 6—Cleaning Heat Exchanger Cell

A91252

—4—

12. Reconnect wires to the following components:

a. Draft safeguard switch

b. Inducer motor

c. Pressure switch

d. Limit overtemperature switch

e. Gas valve

f. Edge connector leading to control box

13. Reconnect vent pipe to relief box. Replace vent pipe

enclosure (downflow furnace only).

14. Replace blower access door only and secure with 2 screws

(downflow furnace only).

15. Turn on electrical power and gas.

16. Set thermostat and check furnace for proper operation.

WARNING: Never use a match or other open flame to

check for gas leaks. Use a soap-and-water solution. A

failure to follow this warning could result in fire, personal

injury, or death.

17. Check for gas leaks.

18. Replace control access door.

D. Electrical Controls and Wiring

NOTE: There may be more than 1 electrical supply to unit.

The electrical ground for 115-v wiring must be maintained

properly. Refer to Fig. 8 for field wiring information and to Fig. 9

for unit wiring information.

With power disconnected to unit, check all electrical connections

for tightness. Tighten all screws on electrical connections. If any

smoky or burned connections are noticed, disassemble the connec-

tion, clean all parts and stripped wire, and reassemble properly and

securely. Electrical controls are difficult to check without proper

instrumentation; therefore, reconnect electrical power to unit and

observe unit through 1 complete operating cycle.

The 24-v circuit contains an automotive-type, 3-amp fuse located

on the main control board. Any direct shorts during installation,

service, or maintenance could cause this fuse to blow. If fuse

replacement is required, use ONLY a 3-amp fuse of identical size.

E. Pilot

Check the pilot and clean if necessary at the beginning of each

heating season. The pilot flame should be high enough for proper

impingement of the flame sensing element (or thermocouple) and

to light the burners. Remove the accumulation of soot and carbon

from the flame sensing element (or thermocouple). Refer to Fig. 7

for proper location of pilot on burner assembly.

F. Troubleshooting

Page 8 contains a troubleshooting chart. This chart can be a useful

tool in isolating furnace operation problems. Beginning with the

word "Start," answer each question and follow the appropriate

arrow to the next item.

The chart will help identify the problem or failed component. After

replacing any component, verify correct operating sequence as

indicated by bold arrows.

Fig. 7—Position of Pilot to Burner

A91249

1/8″

PILOT HEAD V–NOTCH FALLS

DIRECTLY BELOW FRONT EDGE

OF BURNER CARRYOVER.

—5—

Fig. 8—Heating and Cooling Application Wiring Diagram

A78461

115-VOLT FIELD-

SUPPLIED

FUSED

DISCONNECT

AUXILIARY

J-BOX

CONTROL

BOX

24-VOLT

TERMINAL

BLOCK

TWO-WIRE

HEATING-

ONLY

FOUR

WIRE

FIELD-SUPPLIED

FUSED DISCONNECT

CONDENSING

UNIT

TWO

WIRE

FURNACE

R

G

C

W R G Y

GND

GND

FIELD 24-VOLT WIRING

FIELD 115-, 208/230-, 460-VOLT WIRING

FACTORY 24-VOLT WIRING

FACTORY 115-VOLT WIRING

NOTE:

208/230- OR

460-VOLT

THREE

PHASE

208/230-

VOLT

SINGLE

PHASE

WHT

BLK

WHT

BLK

If any of the original wire,

as supplied, must be replaced, use

same type or equivalent wire.

NOTE: Connect Y-terminal as

shown for proper

operation.

W

Y

GND

THERMOSTAT

TERMINALS

—6—

Fig. 9—Unit Wiring Diagram

A92176

FU1

IDR PL1-3

PR-1 PR-2

SEC-1 SEC-2

TRAN

24VAC

115VAC

BLWM

LO

MED LO

MED HI

HI

COM

CAP

L2

COM

4

3

2

1

C

CFRHFR

PL4

NOTE#4

NOTE#8

EAC-1 EAC-2

L1

ILK

EQUIPMENT GROUND

TO 115V AC FIELD DISCONNECTIONS

NOTE #5

NOTE#10

PL2

L1 L2

PL1-1

IDR

PL1-4

ALSFLLS

PL1-7

R

Y

W

G

C

NOTE #1

CFR

NOTE #10

PL1-2PL1-6

NC

NO PRS

C

DSS

TH TR

PILOT

MGV GV PL1-8

TIME

DELAY

LOGIC

HFR

3A

FUSE

PL1-9

(WHEN USED)

NOTE #7

SCHEMATIC

DIAGRAM

MGV

1 4 7

2 5 8

3 6 9

BLWM MED LO

MED HI

HI

COM

LO

CAP

PRS

C

NO

NC

DSS

BRNTH

PILOT

GV

TR

ALS

(WHEN USED)

NOTE #7

FL LS

ORN

YEL

BRN

BLU

RED

BLK

RED

BLU

BLK

BLK

BLU

REDWHT

TRAN

WHT

ILK

NOTE #5

WHT

BLK

IDM

GRN

JB

GRN

BLK

WHT

FU2

FUSED DISCONNECT

SWITCH (WHEN REQ'D)

BRN BRN

WHT

BLK

RED

WHT

BLK

COM

PR2 L2 L1

PR1

HFRCFR

LO

HI

NOTE #10

EAC-1

EAC-2

W Y R C G

NOTE #9

PCB

NOTE #1

GROUND

SCREW

REQ'D

FU1

3AMP

FUSE

NOTE #8

SEC-1

SEC-2

IDR

PL1

CONNECTION

DIAGRAM

JUNCTION

TERMINAL

PCB TERMINAL

FACTORY POWER WIRING (120VAC)

FACTORY CONTROL WIRING (120VAC)

FIELD POWER WIRING (120VAC)

CONDUCTOR ON PCB

FIELD WIRING SCREW TERMINAL

FIELD GROUND

EQUIPMENT GROUND

FIELD SPLICE

PLUG RECEPTACLE

AUX. LIMIT SWITCH (OVER TEMP), SPST-(N.C.),

MANUAL RESET

BLOWER MOTOR

CAPACITOR

COOLING FAN RELAY, SPDT

DRAFT SAFEGUARD SWITCH, SPST-(N.C.), MANUAL RESET

ELECTRONIC AIR CLEANER CONNECTION (115VAC)

ELECTRONIC AIR CLEANER CONNECTION (COMMON)

FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE

FUSE, FIELD INSTALLED

FUSIBLE LINK

GAS VALVE, (REDUNDANT)

HEATING FAN RELAY, SPST (N.O.)

INDUCED DRAFT MOTOR

INDUCER DRAFT RELAY, DPST-(N.O.)

BLOWER DOOR INTERLOCK SWITCH, SPST-(N.O.)

JUNCTION BOX

LIMIT SWITCH (OVER TEMP), SPST-(N.C.), AUTO RESET

PRINTED CIRCUIT BOARD (FURNACE CONTROL)

9-CIRCUIT CONNECTOR (PCB1)

2-CIRCUIT CONNECTOR (L1, L2)

5-CIRCUIT PLUG CONNECTOR (BLWM)

PRESSURE SWITCH, SPDT

TRANSFORMER (115VAC/24VAC)

ALS

BLWM

CAP

CFR

DSS

EAC-1

EAC-2

FU1

FU2

FL

GV

HFR

IDM

IDR

ILK

JB

LS

PCB

PL1

PL2

PL4

PRS

TRAN

LEGEND

NOTES:

1. INTERNALLY CONNECTED TO EQUIPMENT GROUND THROUGH MOUNTING SCREW.

2. IF ANY OF THE ORIGINAL EQUIPMENT WIRE IS REPLACED, USE WIRE RATED FOR

105° C.

3. BLOWER MOTOR (BLWM) & INDUCER MOTOR (IDM) CONTAIN AUTO-RESET

THERMAL OVERLOAD SWITCH.

4. BLOWER MOTOR FACTORY SPEED SELECTIONS (PL4) ARE FOR AVERAGE

CONDITIONS. SEE INSTALLATION INSTRUCTIONS FOR DETAILS ON OPTIMUM

SPEED SELECTIONS.

5. USE ONLY COPPER WIRE BETWEEN THE DISCONNECT SWITCH AND THE

FURNACE JUNCTION BOX (JB).

6. SYMBOLS ARE ELECTRICAL REPRESENTATIONS ONLY.

7. AUXILIARY LIMIT SWITCH (ALS) USED ON DOWNFLOW MODELS ONLY.

8. THE TRANSFORMER 24VAC WINDING IS PROTECTED BY A 3 AMP AUTOMOTIVE

BLADE TYPE FUSE ON THE CONTROL BOARD. A 24VAC SHORT TO GROUND

DURING INSTALLATION, CHECKOUT, OPERATION, SERVICE OR MAINTENANCE

COULD CAUSE THIS FUSE TO OPEN. DO NOT REPLACE THE 3 AMP FUSE

WITH ANY OTHER SIZE FUSE.

9. BLOWER MOTOR (BLWM) ADJUSTABLE OFF-DELAY. FACTORY SET: 120 SECS.

CUT RESISTOR: 180 SECS.

10. WHEN CFR RELAY IS ENERGIZED, HFR RELAY IS ALSO ENERGIZED. 319593-401 REV. C

RED

WHT

4

3

2

1

C

PL2

1

2

NOTE #4

PL4

IDM

IDR

—7—

A91253

Is 24VAC

across pressure

switch N/O contact

& screw C on

board?

YES

NO

Is 24VAC

across pressure

switch N/O contact

& screw C on

board?

Is heat

exchanger

pressure drop greater

than 0.35-in.

wc?

Is

24VAC across gas

valve?

Is

unit lit?

Check/Replace:

1. Vent systems

2. Induce wheel

3. Flue choke

4. Inducer voltage

5. Inducer motor bearings

Check/Replace:

1. Limit switch

2. Limit shield (if used)

3. Fuse link

4. Auxillary limit switch (if used)

5. Wire harness

START

Disconnect all thermostat

wires from board.

Turn on 115-VAC

power to unit.

Is blower

running?

Is 24VAC

across screws

R & C?

Is 24VAC

across screws

W & C or

G & C?

Are

all thermostat

wires to board

disconnected?

Turn off 115-VAC

power to unit.

Replace

board.

Is

115VAC

across L1 &

L2?

Is

24VAC

across screws

R & C?

Is

115VAC

across HI &

COM?

Is

blower running

on cooling

speed?

Jumper across

screws R & G.

Is

115VAC

across EAC-1

& COM?

Replace

board.

Remove

R & G jumper.

Replace

blower motor

and/or start

capacitor.

Check/Replace:

1. Unit power

2. Door switch

3. Power harness

Check/Replace:

1. 3-amp board

fuse

2. Transformer

Check pressure

tube for leak or

crimp; otherwise,

replace pressure switch

Does

blower turn

off?

Jumper across

screws R & W.

Is

24VAC

across PL1-2

& screw C on

board?

Replace

board.

Repair wire

harness.

Check/Replace:

1. Draft safeguard switch

2. Wire harness

Check/Replace:

1. Pilot

2. Thermocouple

3. Gas valve

Is

inducer motor

on?

Replace

inducer motor.

Is

115VAC across

inducer motor

connector?

Is

blower running

on heat speed 45

sec after unit

lights?

Is

115VAC across

inducer motor

connector?

Is

115VAC

across EAC-1

& COM?

Is

24VAC across

PL-2 & screw

C on board?

Check/Repair

wire harness;

otherwise,

replace

pressure

switch.

Replace

board. Remove

R & M jumper. Repair wire

harness.

Is

24VAC

across

PL-1 & screw

C on board?

Replace

blower motor

and/or start

capacitor.

Replace

board.

Check/Replace

thermostat

and/or

thermostat wiring.

After

off-delay

does blower

turn off?

Reconnect all

thermostat wires. Does unit

operate?

END OF TEST.

YES YES

NO NO YES

NO

NO NO

YES NO NO

YES

YES

NO

NO

YES

YES

YES

NO

NO

NO

NO

YES

YES

YES

YES

YESNO

NO

NO

NO

NO

NO

YES

NO

NO

NO

YES

YES

YES

YES

YES

NO

YES

YES

YES

YES

NO

NOTE: After replacing any component, verify correct operating

sequence as indicated by bold arrows.

© 1993 BDP Co. • P.O. Box 70 • Indianapolis, IN 46206 Printed in U.S.A. —8— 35001b Catalog No. BDP-3339-432