hot water from a. o. smith - service handbook ...commercial / residential gas water heater service...

COMMERCIAL / RESIDENTIAL GAS WATER HEATER

Service Handbook

PRINTED IN THE U.S.A. 0410 318556-000

SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE AGENT

500 Tennessee Waltz ParkwayAshland City, TN 37015

FOR MODELS:BTX 100, GDHE 50SERIES 120 & 121

INSTALLATION CONSIDERATIONS - PRE SERVICECHECKS - WATER HEATER CONSTRUCTION -

OPERATION & SERVICE - TROUBLESHOOTING

1

TABLE OF CONTENTSTABLE OF CONTENTS .......................................................................... 1INTRODUCTION .................................................................................... 2

..................................................................................... 2 ................................................................................ 2

.............................................................................. 2 ................................................................................... 2

INSTALLATION CONSIDERATIONS ..................................................... 3 ............................................................................. 3

...................................................................... 3 ............................................................................ 3

............................................................................... 3 ............................................................................... 3

............................................................................................... 4 ....................................................... 4

............................... 4 .................................................................. 5

..................................................................... 6 ............................................................... 6

...................................................................... 6 ........................................................................ 7

......................................................... 8 ........................................................................... 8

............................................................................................ 9 ............................................ 9

OPERATION AND SERVICE ............................................................... 10 ................................................................................... 10

..........................................................................11 ............................................................................. 12

....................................... 14 .................................................................................. 18

......................................................... 18 ...................................................... 19

............................................................................................... 20 .................................................................... 20

Venturi ............................................................................................. 22Gas Valve ........................................................................................ 23

............................................................ 23 ................................................................... 24

Gas Pressure ................................................................................... 25Gas Pressure Test ..................................................................... 26

........................................................................... 27 ........................................................................... 28

.......................................................... 28 ........................................................ 29

..................................................................... 31 ................................................. 31

.............................................. 32 ................................................ 32

.......................................................................... 35 .......................................................... 35

.................................................................. 36

......................................................... 37 ............................................... 37 .............................................. 39

............................. 40 ................................................... 41

........................................... 42 .......................................................................... 44

................................................ 45Overview .................................................................................... 45

.................................................... 45 .................................. 46

.................................................. 46 .............................................................. 46

................................................................... 46 ........................................................................ 47

................................................................. 48 .............................................................. 48

...................................................................... 49Heater Status ...................................................................... 50

.................................................................. 51 .............................................................. 51

Current Fault ....................................................................... 52 ........................................................................ 52

................................................................. 52 .................................................... 52

................................................ 53 ............................................................. 54

.......................................... 55TROUBLESHOOTING ................................................................... 56

........................................ 56 ........................................................ 56

............................................................ 56 ...................................... 56

............................................ 56 ................................................... 57

............................................................. 57 ................................................................ 57

......................................................................... 58AC Reversed ....................................................................... 58

............................................................... 58 ............................................................... 58

............................................................ 59 .............................................................. 59

........................................................ 60 ............................................................... 61

................................................................. 62 .......................................................... 62

............................................................ 63 .............................................................. 64

..................................................................... 65 ....................................................... 66

2

QUALIFICATIONSQUALIFIED INSTALLER OR SERVICE AGENCY

ANSI Z223.1 2006 Sec. 3.3.83:

SERVICE WARNING

SERVICE REMINDER

TOOLS REQUIRED

INTRODUCTION

3

INSTALLATION CONSIDERATIONS

INSTRUCTION MANUAL

CLOSED WATER SYSTEMS

THERMAL EXPANSION

AIR REQUIREMENTS

CONTAMINATED AIR

4

VENTING

GENERAL VENTING INFORMATION

Category IV Appliance

MAXIMUM EQUIVALENT LENGTH REQUIREMENTS

TABLE 12 Inch Pipe 3 Inch Pipe

PIPE SIZE REQUIREMENTS

MAXIMUM ELBOW REQUIREMENTS

2”

3”

= 5 linear feet of pipe

= 5 linear feet of pipe

5

FACTORY SUPPLIED/INSTALLED FITTINGS

INTAKE AIR CONNECTION

Blocked Air IntakeBlocked Air Intake

Blocked Air IntakeBlocked Air Intake

HOSE BARBANGLEDBETWEEN90° AND 115°

HOSE BARB FITTING FORBLOCKED INTAKE AIR

SWITCH SENSING TUBE

COMBUSTION BLOWER

INTAKE AIR CONNECTION24 VOLTGAS VALVE

INTAKE AIRCONNECTION

INTAKE AIRCONNECTION ELBOW

INTAKE AIRCONNECTIONSCREEN MUSTBE REMOVEDON DIRECT VENTINSTALLATIONS

:

Ignition Failure

Blocked Exhaust

Blocked Air Intake

Blocked Air Intake and Blocked Exhaust

Blocked Air Intake and Blocked Exhaust

6

ELECTRICAL REQUIREMENTS

GROUNDING AND POLARITYMUST BE

MUST BE

AC ReversedIgnition Failure

HOT(typically black)

NEUTRAL(typically white)

GROUND(typically green)

120 VOLTS

120 VOLTS

0 VOLTS

120 VAC POWER SUPPLY POLARITY CORRECT WIRING120 VAC WALL OUTLET

PLUG IN OUTLET TESTER

NEUTRAL HOT

GROUND

POWER SUPPLY TEST

1. 2. 3.

7

INSTALLATION CHECK LIST

1.

2. 3.

Blocked Exhaust Blocked Air Intake

4.


5.


6.

Blocked Exhaust

7.

8.

9.

10.

11.

AC Reversed

12.

Ignition Failure

8

FEATURES AND COMPONENTSFRONT & BACK VIEWS

HEATING LOOPRETURN LINECONNECTION3/4 INCH NPT

DRAIN VALVE

TEMPERATUREPRESSURERELIEF VALVE

FRONT VIEW BACK VIEW

EXHAUST ELBOW(2 INCH PVC VENTCONNECTION)

CONDENSATEDRAIN CONNECTION

BLOCKED EXHAUSTSWITCH SENSING TUBE

HEATING LOOPSUPPLY LINECONNECTION3/4 INCH NPT

2 INCH PVCINTAKE AIRCONNECTION

TOP COVER

ON / OFF SWITCH

UIM(user interface module)

CONTROL INTERFACECOVER.

TEMPERATUREPROBE - LOCATEDBEHIND CONTROLINTERFACE COVER

TANK GLASSINGPLUG COVER.USED FORMANUFACTURINGPURPOSES ONLY.

DO NOT REMOVEGLASSING PLUGFOR ANY SERVICEOR MAINTENANCE.

COVER MAY BEREMOVED IF LEAKIS SUSPECTED.

9

TOP VIEW

BLOWERPROVERSWITCH

CCB ENCLOSURE(central control board)

3/4 INCH NPTWATER OUTLETWITH OUTLETANODE ROD

3/4 INCH NPTWATER INLET

BLOCKEDEXHAUSTSWITCH

TEMPERATUREPRESSURERELIEF VALVE

BURNERSIGHT GLASS

FRONT

1/2 INCHSUPPLY GASCONNECTION

BLOCKEDINTAKE AIRSWITCH

COMBUSTIONBLOWER

2 INCH PVCINTAKE AIRCONNECTION

2 INCH PVCVENT CONNECTION

JUNCTIONBOX - 120 VACPOWER SUPPLYCONNECTIONS

SECONDANODE ROD

COMBUSTION BLOWER & BURNER ASSEMBLY

COMBUSTIONBLOWER

EXPLODED VIEW

GASKET(SILICONE)

BLOWERDISCHARGE

ORIFICE

GASKET(FIBER)

BURNER SIGHTGLASS AND

WIRING HARNESSCOVER PLATE

GASKET (SILICONE)

GASKET

GASKET (FIBER)

GASKET (FIBER)

BURNER SIGHT GLASS

BURNERADAPTER

BURNER ADAPTERWIRING HARNESS.IGNITER/FLAMESENSOR

IGNITER

BURNER

BURNER FLANGE(FLOATING FLANGE)

FLAMESENSOR

GAS VALVEVENTURI ASSEMBLY

INTAKE AIRELBOW

ASSEMBLED VIEW

10

OPERATION AND SERVICE

HOW IT WORKS

BLOWER/BURNERGAS VALVEASSEMBLY

COMBUSTIONAIR INTAKECONNECTION

HELICAL SHAPEHEAT EXCHANGER

ARROWS SHOWPATH OF FLUEGASES THROUGHTHE HEATEXCHANGER

EXHAUST/VENTOUTLET

INTERNAL VIEW

11

COMBUSTION BLOWER

Service Note:

Ignition Failure

BLOWER MOTORAND ELECTRONICSPEED CONTROL

COMBUSTION BLOWER ASSEMBLY

BLOWERHOUSING

3 PINWIRING

SOCKET

5 PINWIRINGSOCKET

12

BURNER ASSEMBLY

BURNER ADAPTERWIRING HARNESSIGNITER/FLAMESENSOR

BLOWERFLANGE

BURNERADAPTER

BURNERFLANGE &GASKET

BURNER

BURNER ASSEMBLYRIGHT SIDE VIEW

FLAMESENSOR


BLOWERFLANGE

BURNERADAPTER

BURNERFLANGE &GASKET

BURNER

BURNER ASSEMBLYLEFT SIDE VIEW

IGNITER

13

BURNER GROUNDWIRE

BURNERADAPTER

BLOWER FLANGE WITH BLOWERDISCHARGE ORIFICE IN PLACE

BURNER ADAPTERWIRING HARNESSIGNITER/FLAME SENSOR

BURNER SIGHTGLASS


BLOWERDISCHARGEORIFICE

BLOWER FLANGE WITHORIFICE REMOVED

BLOWERDISCHARGEORIFICE

BLOWERFLANGE

WIRINGHARNESSGROMMET

BURNERADAPTER


14

COMBUSTION BLOWER AND BURNER REMOVAL

Ignition Failure

ORANGE SILICONE GASKET BETWEEN THE COMBUSTIONBLOWER AND THE BLOWER FLANGE ON THE BURNER ADAPTER

WHITE FIBER GASKET BETWEEN THE BURNER ADAPTER AND THETHE HEAT EXCHANGER FLANGE ON TOP OF THE STORAGE TANK

COMBUSTION BLOWER REMOVAL1.

2. 3.

4. 5.

15

6.

7.

8. 9. 10.

11.

12.

13. 14. 15.

16. COMBUSTION BLOWER INSTALLATION17. 18. 19.

20.

INTAKE AIR CONNECTION FITTING

VENTURI

COMBUSTION BLOWER ASSEMBLY TOP VIEW

HOSECLAMP

INTAKE AIRELBOW

COMBUSTION BLOWEROUTLET SENSING PORT

24 VOLT GAS VALVEWIRING HARNESS

SPADE CONNECTORS

SUPPLY GAS CONNECTION

24 VOLT GAS VALVE

COMBUSTIONBLOWER

16

BURNER ASSEMBLY REMOVAL1. 2. 3.

4.

5.

6.

7.

8.

9. 10. 11.

12.

13. 14. 15.

16.

17

BURNER ASSEMBLY INSTALLATION17. 18.

19.

20.

FOUR 1/2 INCHNUTS AND STUDS

BURNERGROUNDWIRE

BURNER SIGHT GLASSWIRING HARNESS COVERPLATE AND GASKET.

TWO PHILLIPS HEADSCREWS HOLD COVERPLATE AND GASKET INPLACE.

18

FLAME SENSOR

FLAME SENSING OPERATION

The Burner MUST BE

IGNITER

BURNERFLAME

BURNER(MUST BE GROUNDED)

CERAMIC INSULATOR

FLAME SENSOR

METAL CONDUCTOR

CONTROL SYSTEMAPPLIES AC VOLTAGETO FLAME SENSOR

AC VOLTAGE FLOWS FROM THE FLAME SENSOR TO THE BURNER. THE BURNERMUST BE GROUNDED FOR CURRENT TOFLOW. DURING THIS PROCESS THE ACVOLTAGE IS “RECTIFIED” AND BECOMES A DC VOLTAGE. DC MICRO AMP CURRENTTHEN FLOWS BETWEEN THE FLAME SENSORAND THE BURNER.

GAP BETWEEN THE FLAME SENSOR AND THEBURNER SHOULD BE APPROXIMATELY 1/2 INCH

MINIMUM FLAME SENSING CURRENT

Ignition Failure

19

FLAME SENSING CURRENT TEST

FLAME SENSOR

CERAMIC INSULATOR

FLAME SENSING TEST BEHINDTHE CCB ENCLOSURE

FLAME SENSING TEST INSIDETHE CCB ENCLOSURE

CCB J4 FLAME SENSORCONNECTION

IGNITER/FLAME SENSORWIRING HARNESS FROM CCB

WIRE FROMFLAME SENSOR

WIRE FROMFLAME SENSOR

:

Ignition Failure

Ignition Failure

20

IGNITER

Low Igniter Current

IGNITER CURRENT TEST1.

2. 3. 4.

5.

21

IGNITER CURRENT TEST AT J5 SOCKET ON CCB

IGNITER CURRENT TEST BEHIND CCB ENCLOSURE

22

VENTURI

Negative Pressure

Negative Pressure

Velocity IncreasesAt Constriction Point

Pressure Drops

GA

SVA

LVE

Combustion Air

VENTURI

VENTURI INLET

GAS INLET24 VOLT GAS VALVE

BLOWER

BLOWER

SUPPLY GAS

BURNER

23

GAS VALVE

VENTURI

24 VOLT GAS VALVE ASSEMBLY TOP VIEW

24 VAC FROM THE J6 SOCKETON THE CCB CONNECTS TOTHESE TWO SPADE TERMINALSAT THE END OF THE 24 VOLTGAS VALVE WIRING HARNESS.

SUPPLY GAS CONNECTION

24 VOLT GAS VALVE

PLUG RETAININGSCREW

24 VOLT GAS VALVEWIRING HARNESS

24 VOLT GAS VALVE WIRINGHARNESS PLUG. 24 VACFROM CCB IS RECTIFIED TO24 VDC BY ELECTRONICSINSIDE THE PLUG END.

COMBUSTIONBLOWER

GAS VALVE VOLTAGE TESTS1.

2.

AC VOLTAGE TEST DC VOLTAGE TEST

24

GAS VALVE REMOVAL

1.

2. 3.

4. 5. 6.

7.

8. 9. 10. 11.

24 VOLT GAS VALVE

VENTURI

5/32 INCHHEX WRENCH

GAS ORIFICE& GASKET

GAS ORIFICE

GAS ORIFICE SIZESNATURAL GAS: 0.191”PROPANE GAS: 0.162”

GASKET

25

GAS PRESSURE

TABLE 2

NATURAL GAS PROPANE GAS NATURAL GAS PROPANE GAS NATURAL GAS PROPANE GAS

Ignition Failure

VENTURI

SUPPLY GASCONNECTION

PRESSURETEST PORTS

COMBUSTIONBLOWERCONNECTION

24 VOLT GAS VALVE

COMBUSTIONAIR INLET

26

GAS PRESSURE TEST1.

2. 3. 4.

5.

6. 7.

8. 9. 10. 11.

12. 13.

14. 15. 16. 17.

18. 19. 20.

MANIFOLD OFFSETPRESSURE TEST PORT

SUPPLY GASPRESSURETEST PORT

27

GAS FLOW TEST

CONDITIONS:

:GAS:

.C.

.C.

AT

AT

ATTING3

CONDITIONS:

:GAS:

.C.

.C.

CONDITIONS:

:GAS:

.C.

.C.

28

PRESSURE SWITCHES

CONSTRUCTION & OPERATION

Vent Port

Sensing PortFlexible Diaphragm

Wiring TerminalsSwitch Contacts

Normal State(open switch contacts)

Activated State(closed switch contacts)

Internal Linkage

Normal State Activated State

Blower Prover Pressure Switch

Normally open contacts ,close on a rise in pressure .

Blocked ExhaustPressure Switch

Normally closed contacts, open on a rise in pressure .

Blocked Intake Air Pressure Switch

Normally closed contacts,open on a fall in pressure .

CONSTRUCTION

TYPES AND APPLICATION

29

CONTROL SYSTEM MONITORING

Blower Prover FailureBlower Prover Open

Blocked Air Intake Blocked Exhaust

CHANGE BACK ADVANCED

Blower Prover FailureFault occurred 2 mins ago

The blower prover switch isclosed out of sequence.

Call a service professional:Your Company Name Here(press [DOWN] for more....)


Blower Prover OpenFault occurred 2 mins ago

The blower prover switch remainsopen after the blower has beenenergized.



Blocked Air IntakeFault occurred 2 mins ago

The combustion air intake isrestricted.



Blocked ExhaustFault occurred 2 mins ago

The exhaust is blocked orrestricted. Ensurecondensate hose is draining.


PRESSURE SWITCH FAULT MESSAGES

30

Blower Prover Open, Blower Prover Failure, Blocked Air Intake Blocked Exhaust

BLOWER PROVER BLOCKED INTAKE AIR

PRESSURE SWITCH SENSING TUBE CONNECTIONS

BLOCKED EXHAUST BLOCKED EXHAUST

31

PRESSURE SWITCH TESTS

CONTINUITY TEST DURING STANDBY

1.

2. 3. 4.

32

CONTINUITY TEST DURING OPERATION

1. 2.

3. 4.

5.

6.

7. 8.

PRESSURE TEST DURING OPERATION

33

TABLE 3

Blower Prover Blocked Intake Air

1. 2. 3.

4.

5. 6. 7. 8.

Blower Prover:AND

IS NOT

Blocked Intake Air:

AND

IS NOT

AND

IS NOT

34

BLOWER PROVER SWITCHPRESSURE TEST

BLOCKED INTAKE AIR SWITCHPRESSURE TEST

BLOCKED EXHAUST SWITCHPRESSURE TEST

35

TEMPERATURE PROBE

ECO HIGH TEMPERATURE LIMIT SWITCH

Energy Cut Out (ECO)

TEMPERATURE SENSOR

Temp Probe ShortTemp Probe Open

TEMPERATURE SENSOR TEST1. 2. 3.

4. 5.

36

WATER TEMPERATURE TEMPERATURE SENSOR RESISTANCE IN OHMSCELSIUS FAHRENHEIT

26,43511,9745,8623,7803,0662,5031,6981,177

ECO CONTINUITY TEST1. 2. 3.

4. 5. 6.



37

CONTROL SYSTEM HARDWARE

COMPONENTS

UIM CIRCUIT BOARD BACK

J3 SOCKET - BUTTONPAD COMMUNICATION

BUTTON PAD OVERLAY

J3 SOCKET - ENSURECABLE IS PLUGGED INEXACTLY AS SHOWN

UIM CIRCUIT BOARD FRONT

J2 SOCKET - CCBCOMMUNICATIONCAT V CABLE

LCD SCREEN

38

UIM RIBBON CABLE CONNECTION

RIBBON CABLE PLUG END

METAL CRIMPCONNECTIONS

FRONT SIDE BACK SIDE

39

CCB ENCLOSURE WITH FRONT REMOVEDCCB CIRCUIT BOARD

120 VAC X 24 VAC50 VA TRANSFORMER

CCB ENCLOSURE

FRONT COVER ON

FRONT

TOP OF WATER HEATER FRONT COVER REMOVED

CCB CIRCUIT BOARD MOLDED CLIPS

RAISED EDGES (3)FOR WIRINGSTRAIN RELIEF

COVER SCREWS (2)CCB ENCLOSURE TRANSFORMER COVER

40

CCB COVER REMOVAL AND REPLACEMENT

1. 2. 3. 4.

1.

2. 3. 4.

5.

41

CCB CIRCUIT BOARD LAYOUT

1 Retry

Use Yes

Type Tstat

Spare

ExtInput

3Retries

No

Vent

Spare

OPE

N

1

2 3

4

3

2

1

6

5

4

9

8

7

12

11

10

15

14

13

J6

J7 3 24 1

1

2

J15

84

5

6

7

1

2

3

J13

3

4

1

2

J10

1

3

5

2

4

J1

1

3

4

2

J2

1

4

2 1

2

J3 J5 J4

S1 DIPSWITCH

J16

J9

J11

S1 DIPSWITCH DETAIL

CCB (CENTRAL CONTROL BOARD)

1 Retry

Use Yes

Type Tstat

Spare

ExtInput

3Retries

No

Vent

Spare

OPE

N

1

2 3

4

Dipswitch Operation:Along one side of the dipswitch array there are numbers, 1-4. On the other side of the dipswitchis the word “OPEN.” The dipswitches are rocker type switches, if one side of the rocker is down the other side will be up. Pressing a rocker down on the side of the array labeled “OPEN,” opens the switch.Pressing a rocker down on the side of the array labeled with the numbers 1-4 closes the dipswitch.

CHANGING NUMBER OF IGNITION TRIALS BEFORE LOCK OUT

NOTE: Always turn off power to the water heater before changing dipswitch settings.

Set dipswitch #4 to the open position for 1 trial for ignition before Ignition Failure lock out. Set dipswitch#4 to the closed position for 3 trials for ignition before Ignition Failure lock out.

42

CCB CONNECTION IDENTIFICATION

PIN # DESCRIPTION12345


PIN # DESCRIPTION123 120 VAC neutral

PIN # DESCRIPTION12 120 VAC neutral

PIN # DESCRIPTION123456789101112131415

43


J13 Socket - Blower Speed Control


44

WIRING DIAGRAM

2 GREEN

WHITE

RED BLACK

1

1

2

BLACK

3

WHITE

COMBUSTIONBLOWER

TEMPERATURE PROBE

1 RED (ECO)

4 RED (ECO)

2 BLACK3 BLACK

1 BLACK120 VAC HOT

3 WHITE 120 VAC NEUTRAL4 YEL 24 VAC

4 YEL 24 VAC

HOT SURFACE IGNITER

FLAME SENSOR

BLOCKED INTAKE AIR

BLOCKED EXHAUST

BLOWER PROVER

24 VOLT GAS VALVE

B (C

EN

TR

AL C

ON

TR

OL B

OA

RD

)C

C6J

5J4J

7J51

J

61J

01J

31J

2J3J

1J

TRANSFORMER INSIDE CCBENCLOSURE50VA

GROUND STRIPBURNER GROUND(BURNER BOLT)

ON/OFFSWITCH

GROUND

120 VAC NEUTRAL

120 VAC HOT

1 BLACK2 WHITE

RED

1 BLACK

2 WHITE

MU

SE

R IN

TER

FAC

E M

OD

ULE

IU

21541451067

811

LN

1 4 5

3 WHITE/GREEN

7 WHITE/BLUE

8 WHITE/BROWN

2 RED

GREENWHITE

NOIT

CN

UJX

OB

NE

ER

G

NE

ER

G

ENABLE/DISABLE CIRCUITJUMPER WIRE BETWEEN PINS8 AND 11 ON J6 PLUG

NOTE: COMBUSTION BLOWERASSEMBLY CONSISTS OF MOTOR, BLOWER AND INTEGRALBLOWER SPEED CONTROL.

PWM (Pulse Width Modulation)SPEED INSTRUCTION SIGNALWIRES FROM CCB TO BLOWERSPEED CONTROL

120 VAC 1 Ø POWER

AC Reversed

Ignition Failure

45

CONTROL SYSTEM OPERATIONOVERVIEW

CONTROL SYSTEM FEATURES

EMI / RFI Filtering:

46

COMMERCIAL AND RESIDENTIAL MODELS

CONTROL SYSTEM NAVIGATION

USER INPUT BUTTONS

DESKTOP SCREEN

Tank Temperature 103°FOperating Set Point 120°FStatus: Heating

MENU HELP

GAS

OFFON

MANUFACTURER / MODEL INFORMATIONLCD ScreenInformationDisplay

Status Icons

3 Operational buttons:enter/exit menus,select menu items,activate adjustment modes,confirm/cancel changes.

Up & Down buttons:navigate menus,adjust user settings

Title Bar

Operational buttons are multifunctional. Their current function is defined bythe text that appears directly above each button on the LCD screen.

UIM (user interface module)Desktop Screen Shown

UP

DN

47

STATUS ICONS

TABLE 5Icon

GAS

OFFON

NOTE:

48

OPERATING STATES

TABLE 6State

NOTE:

Fault

NOTE:

CONTROL SYSTEM MENUS

Heater Status

Current Fault

NOTE:

49

TEMPERATURES

NOTE:

DESCRIPTION/ACTION DISPLAY

Tank Temperature 120°FOperating Set Point 120°FStatus: Standby

MENU HELP

MANUFACTURER / MODEL INFORMATION

TemperaturesHeater StatusDisplay SettingsHeater InformationCurrent Fault

SELECT BACK HELP

Main Menu

NOTE:

Operating Set Point 120°FDifferential 8°FTank Temperature 120°FTank Probe Offset 0°F

CHANGE BACK HELP

Temperatures

NOTE:


UPDATE CANCEL

Temperatures

50

TEMPERATURES MENU


NOTE:


CHANGE BACK HELP

Temperatures

HEATER STATUS


ECO Contact, Blocked Inlet PS, , Blower Prover PS

Blower Low On, Blower High On

Igniter On,

Ignition Failure

Status StandbyECO Contact ClosedBlocked Inlet PS ClosedBlocked Outlet PS ClosedBlower Prover PS OpenBlower Low On NoBlower High On No

BACK HELP

Heater Status

Blower High On NoIgniter On NoIgniter Current NoGas Valve On NoFlame Detected NoExternal Input Enable NoIgnition Trials 3

BACK HELP

Heater Status

51

DISPLAY SETTINGS


Backlight Delay

NOTE:

Temperature Units °FBacklight Delay 30sContrast 60%

CHANGE BACK HELP

Display Settings

HEATER INFORMATION


NOTE:

water heater.

Elapsed Time 10 day 0 hrs 0 minsBurner On Time 5 hrs 22 minsCycle Count 00000035CCB Version X.XXUIM Version X.XX

CHANGE BACK HELP

Heater Information

52

CURRENT FAULT






FAULT HISTORY


NOTE:

1: Blocked Air Intake (A7) 51 mins ago2: Blocked Exhaust (A8) 54 mins ago3: Low Gas Pressure (A6) 57 mins ago4: Blower Prover Failure (AC)

VIEW BACK HELP

Fault History

FAULT OCCURRENCE


installed.NOTE:

Ignition Failure 10ECO 0Blocked Intake Air 0Blocked Exhaust 0Thermostat Input 4 0Blower Prover 3Flame Detect Error 0

BACK HELP

Fault Occurrence

RESTORE FACTORY DEFAULTS


YES NO

Restore Factory Defaults

Are you sure you want torestore the system to factorydefaults?

53

SERVICE CONTACT INFORMATION


it. Show Contact Information NoChange Contact NameChange Contact PhoneCurrent Contact Info:

(000) 000-0000Access Code

CHANGE BACK HELP

Service Contact Information

NOTE:

Show Contact Information YesChange Contact NameChange Contact PhoneCurrent Contact Info:


UPDATE CANCEL


Show Contact Information YesChange Contact NameChange Contact PhoneCurrent Contact Info:


SELECT BACK HELP


Enter the service contact below:

NAME: _

Use the > and < keys to move betweencharacters. Use the UP and DOWN keys tochange the character.

- -

< > UPDATE- -

BACK HELP

Show Contact Information YesChange Contact NameChange Contact PhoneCurrent Contact Info:YOUR COMPANY NAME HERE(123) 456-7890Access Code


54

SEQUENCE OF OPERATION

1.

2.

3.

4.

5.

6.

the Blower Prover Open7.

8.

Low Igniter Current9.

10. 11.

12. Ignition Failure

13.

14.

15.

16.

55

SEQUENCE OF OPERATION FLOW CHART

If tank temperature drops below Operating Set Point minusDifferential setting a heating cycle is activated

Control System performs diagnostic system checkNormal State of all pressure switches and ECO are checked

Blower Prover pressure is switch verified openAll other pressure switches and ECO are verified closed

Blower Prover switch contacts confirmedclosed by Control System

Igniter is energized for warm up period

YES

24 Volt Gas Valve is energizedgas flows to Burner

Does Control System sense minimum flame sensingof 1.0 μA (DC micro amps) through Flame Sensor?

Control System Locks OutDisplays Fault Msg

Combustion Blower is energizedPre-Purge cycle

YES

Does Control System sense minimum0.5 AC amps through the Igniter?

YES

Control System Locks Out“Blower Prover Open”Fault Msg is displayed

NO

Control System Locks Out“Low Igniter Current”

Fault Msg is displayedNO

YES NO

Water is heated toset point

24 Volt Gas Valvede-energized

30 secondInter-Purge cycle

24 Volt Gas Valvede-energized

Retries up totwo more times

30 secondPost-Purge cycle

Control System Locks Out“Ignition Failure”

Fault Msg is displayed

Control System goesinto Standby mode

NO

56

TROUBLESHOOTING

ROUGH STARTING/ROUGH OPERATION

NOT ENOUGH HOT WATER

HEATER STATUS MENU

THINGS TO CHECK BEFORE SERVICING

NOTE:

RESETTING THE CONTROL SYSTEM

IMPORTANT SERVICE REMINDER

57

CONTROL SYSTEM UNRESPONSIVEDISPLAYED MESSAGE/CONDITION/INDICATES POSSIBLE CAUSES - CHECK/REPAIR

water heater.

58

FAULT MESSAGESDISPLAYED MESSAGE/CONDITION/INDICATES POSSIBLE CAUSES - CHECK/REPAIR


AC ReversedFault occurred 2 mins ago

Power supply to water heaterhas reversed polarity.



Temp Probe OpenFault occurred 2 mins ago

There is a problem with thetemperature probe.



Temp Probe ShortFault occurred 2 mins ago

There is a problem with thetemperature probe.


59



Flame Sensor ShortFault occurred 2 mins ago

The flame sensor is grounded.



Flame Detect ErrorFault occurred 2 mins ago

Flame detected out of sequence.


60



Energy Cut Out (ECO)Fault occurred 2 mins ago

Tank temperature is excessive.The water heater has beendisabled.


DO NOT LEAVE THE WATER HEATER IN OPERATION UNDER ANY

DO NOT LEAVE THE WATER HEATER IN OPERATION UNDER ANY

61


Blocked Air Intake


Blocked Air IntakeFault occurred 2 mins ago

The combustion air intake isrestricted.


62







Blower Prover FailureFault occurred 2 mins ago

The blower prover switch isclosed out of sequence.


63


Blower Prover Open





PERFORM ALL THESE TESTS WITH POWER TURNED ON AND A CALL FOR HEAT ACTIVE.

end.

Blower Prover Open





30.

64



Low Igniter CurrentFault occurred 2 mins ago

Igniter current is low.


65



Ignition FailureFault occurred 2 mins ago

The water heater has failed toignite the burner.


PROCEED TO THE NEXT PAGE

66



Ignition FailureFault occurred 2 mins ago

The water heater has failed toignite the burner.


Ignition Failure


Communication FailureFault occurred 2 mins ago

Communications between theuser interface module and thecentral control board could notbe established.Call a service professional:Your Company Name Here(press [DOWN] for more....)

500 Tennessee Waltz Parkway, Ashland City, TN 37015

hot water from a. o. smith - service handbook ...commercial / residential gas water heater service...

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